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  6.     <title>3.¬† Brush Tools</title>
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  13.     <link rel="up" href="gimp-toolbox.html" title="Chapter¬†13.¬† Toolbox" />
  14.     <link rel="prev" href="gimp-tool-foreground-select.html" title="2.8.¬† Foreground Select" />
  15.     <link rel="next" href="gimp-tool-painting.html" title="3.2.¬† Painting Tools (Pencil, Paintbrush, Airbrush)" />
  16.   </head>
  17.   <body>
  18.     <div class="navheader">
  19.       <table width="100%" summary="Navigation header">
  20.         <tr>
  21.           <th colspan="3" align="center">3.¬†
  22.     <span lang="en" xml:lang="en">Brush Tools</span>
  23.   </th>
  24.         </tr>
  25.         <tr>
  26.           <td width="20%" align="left"><a accesskey="p" href="gimp-tool-foreground-select.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  27.           <th width="60%" align="center">Chapter¬†13.¬†
  28.         <span lang="en" xml:lang="en">Toolbox</span>
  29.       </th>
  30.           <td width="20%" align="right">¬†<a accesskey="n" href="gimp-tool-painting.html"><img src="../images/next.png" alt="Next" /></a></td>
  31.         </tr>
  32.       </table>
  33.       <hr />
  34.     </div>
  35.     <div class="sect1" lang="en" xml:lang="en">
  36.       <div class="titlepage">
  37.         <div>
  38.           <div>
  39.             <h2 class="title" style="clear: both"><a id="gimp-tools-paint"></a>3.¬†
  40.     <span lang="en" xml:lang="en">Brush Tools</span>
  41.   </h2>
  42.           </div>
  43.         </div>
  44.       </div>
  45.       <div class="sect2" lang="en" xml:lang="en">
  46.         <div class="titlepage">
  47.           <div>
  48.             <div>
  49.               <h3 class="title"><a id="gimp-tool-brush"></a>3.1.¬†
  50.     <span lang="en" xml:lang="en">Common Features</span>
  51.   </h3>
  52.             </div>
  53.           </div>
  54.         </div>
  55.         <a id="id2626996" class="indexterm"></a>
  56.         <a id="id2627005" class="indexterm"></a>
  57.         <div class="figure">
  58.           <a id="id2627018"></a>
  59.           <p class="title">
  60.             <b>Figure¬†13.31.¬†
  61.       <span lang="en" xml:lang="en">The Paint Tools (Tools menu)</span>
  62.     </b>
  63.           </p>
  64.           <div class="figure-contents">
  65.             <div class="mediaobject">
  66.               <img src="../images/toolbox/brush-tools.png" alt="The Paint Tools (Tools menu)" />
  67.             </div>
  68.           </div>
  69.         </div>
  70.         <br class="figure-break" />
  71.         <p>
  72.     The GIMP Toolbox includes thirteen ‚Äú<span class="quote">brush tools</span>‚Äù,
  73.     all grouped together at the bottom (in the default arrangement).
  74.   </p>
  75.         <div class="figure">
  76.           <a id="id2627058"></a>
  77.           <p class="title">
  78.             <b>Figure¬†13.32.¬†
  79.       <span lang="en" xml:lang="en">The Paint Tools (Tools Box)</span>
  80.     </b>
  81.           </p>
  82.           <div class="figure-contents">
  83.             <div class="mediaobject">
  84.               <img src="../images/toolbox/brush-tools-box.png" alt="The Paint Tools (Tools Box)" />
  85.             </div>
  86.           </div>
  87.         </div>
  88.         <br class="figure-break" />
  89.         <p>
  90.     The feature they all have in common is that all of them are used by moving
  91.     the pointer across the image display, creating brush-strokes. Four of them
  92.   </p>
  93.         <div class="itemizedlist">
  94.           <ul type="disc">
  95.             <li>
  96.               <p>
  97.         the <a class="link" href="gimp-tool-pencil.html" title="3.5.¬† Pencil">Pencil</a>,
  98.       </p>
  99.             </li>
  100.             <li>
  101.               <p>
  102.         the <a class="link" href="gimp-tool-paintbrush.html" title="3.6.¬† Paintbrush">Paintbrush</a>,
  103.       </p>
  104.             </li>
  105.             <li>
  106.               <p>
  107.         the <a class="link" href="gimp-tool-airbrush.html" title="3.8.¬† Airbrush Tool">Airbrush</a> and
  108.       </p>
  109.             </li>
  110.             <li>
  111.               <p>the <a class="link" href="gimp-tool-ink.html" title="3.9.¬† Ink">Ink tool</a></p>
  112.             </li>
  113.           </ul>
  114.         </div>
  115.         <p>
  116.     behave like the intuitive notion of "painting" with a brush. The others
  117.     use a brush to modify an image in some way rather than paint on it:
  118.   </p>
  119.         <div class="itemizedlist">
  120.           <ul type="disc">
  121.             <li>
  122.               <p>
  123.         the <a class="link" href="gimp-tool-bucket-fill.html" title="3.3.¬† Bucket Fill">Bucket Fill</a> fills
  124.         with color or pattern;
  125.       </p>
  126.             </li>
  127.             <li>
  128.               <p>
  129.         the <a class="link" href="gimp-tool-blend.html" title="3.4.¬† Blend">Gradient</a> fills with
  130.         gradients;
  131.       </p>
  132.             </li>
  133.             <li>
  134.               <p>
  135.         the <a class="link" href="gimp-tool-eraser.html" title="3.7.¬† Eraser">Eraser</a> erases;
  136.       </p>
  137.             </li>
  138.             <li>
  139.               <p>
  140.         the <a class="link" href="gimp-tool-clone.html" title="3.10.¬† Clone">Clone tool</a> copies from a
  141.         pattern, or image;
  142.       </p>
  143.             </li>
  144.             <li>
  145.               <p>
  146.         the <a class="link" href="gimp-tool-perspective-clone.html" title="3.12.¬† Perspective Clone">Perspective
  147.           Clone</a> tool copies into a changed perspective;
  148.       </p>
  149.             </li>
  150.             <li>
  151.               <p>
  152.         the <a class="link" href="gimp-tool-heal.html" title="3.11.¬† Heal">Heal tool</a> corrects small
  153.         defects;
  154.       </p>
  155.             </li>
  156.             <li>
  157.               <p>
  158.         the <a class="link" href="gimp-tool-convolve.html" title="3.13.¬† Convolve (Blur/Sharpen)">Convolve tool</a>
  159.         blurs or sharpens;
  160.       </p>
  161.             </li>
  162.             <li>
  163.               <p>
  164.         the <a class="link" href="gimp-tool-smudge.html" title="3.14.¬† Smudge">Smudge tool</a> smears;
  165.       </p>
  166.             </li>
  167.             <li>
  168.               <p>
  169.         and the <a class="link" href="gimp-tool-dodge-burn.html" title="3.15.¬† Dodge or Burn">Dodge/Burn tool</a>
  170.         lightens or darkens.
  171.       </p>
  172.             </li>
  173.           </ul>
  174.         </div>
  175.         <p>
  176.     The advantages of using GIMP with a tablet instead of a mouse
  177.     probably show up more clearly for brush tools than anywhere else:
  178.     the gain in fine control is invaluable.  These tools also have
  179.     special ‚Äú<span class="quote">Pressure sensitivity</span>‚Äù options that are only usable
  180.     with a tablet.
  181.   </p>
  182.         <p>
  183.     In addition to the more common ‚Äú<span class="quote">hands-on</span>‚Äù method, it is
  184.     possible to apply brush tools in an automated way, by creating a
  185.     selection or path and then ‚Äú<span class="quote">stroking</span>‚Äù it.  You can choose to
  186.     stroke with any of the brush tools, including nonstandard ones
  187.     such as the Eraser, Smudge tool, etc., and any options you set for
  188.     the tool will be applied.  See the section on <a class="link" href="gimp-selection-stroke.html" title="6.17.¬† Stroke Selection">Stroking</a> for more information.
  189.   </p>
  190.         <div class="sect3" lang="en" xml:lang="en">
  191.           <div class="titlepage">
  192.             <div>
  193.               <div>
  194.                 <h4 class="title"><a id="gimp-tools-brush-modifiers"></a>3.1.1.¬†
  195.       <span lang="en" xml:lang="en">Key modifiers</span>
  196.     </h4>
  197.               </div>
  198.             </div>
  199.           </div>
  200.           <div class="variablelist">
  201.             <dl>
  202.               <dt>
  203.                 <span class="term">
  204.           <span class="keycap"><strong>Ctrl</strong></span>
  205.         </span>
  206.               </dt>
  207.               <dd>
  208.                 <p>
  209.             Holding down the <span class="keycap"><strong>Ctrl</strong></span> key has a special effect on
  210.             every brush tool . For the Pencil,
  211.             Paintbrush, Airbrush, Ink Tool, Eraser, and Smudge tools, it
  212.             switches them into ‚Äú<span class="quote">color picker</span>‚Äù mode, so that
  213.             clicking on an image pixel causes GIMP's foreground to be set to the
  214.             active layer's color at that point (or, for the Eraser, GIMP's
  215.             background color). For the Clone tool, the <span class="keycap"><strong>Ctrl</strong></span> key
  216.             switches it into a mode where clicking sets the reference point
  217.             for copying. For the Convolve tool, the <span class="keycap"><strong>Ctrl</strong></span> key
  218.             switches between blur and sharpen modes; the the Dodge/Burn tool, it switches between dodging and burning.
  219.           </p>
  220.               </dd>
  221.               <dt>
  222.                 <span class="term">
  223.           <span class="keycap"><strong>Shift</strong></span>
  224.         </span>
  225.               </dt>
  226.               <dd>
  227.                 <a id="id2627466" class="indexterm"></a>
  228.                 <p>
  229.             Holding down the Shift key has the same effect on all brush tools:
  230.             it places the tool into <span class="emphasis"><em>straight line</em></span>
  231.             mode. To create a straight line with any of the brush tools, first
  232.             click on the starting point, <span class="emphasis"><em>then</em></span>
  233.             press the Shift key. As long as you hold it down, you will see a
  234.             thin line connecting the previously clicked point with the current
  235.             pointer location. If you click again, while continuing to hold
  236.             down the Shift key, a straight line will be rendered. You can
  237.             continue this process to create a series of connected line
  238.             segments.
  239.           </p>
  240.               </dd>
  241.               <dt>
  242.                 <span class="term">
  243.           <span class="keycap"><strong>Ctrl</strong></span>+<span class="keycap"><strong>Shift</strong></span>
  244.         </span>
  245.               </dt>
  246.               <dd>
  247.                 <p>
  248.             Holding down both keys puts the tool into
  249.             <span class="emphasis"><em>constrained straight line</em></span> mode.  This
  250.             is similar to the effect of the Shift key alone, except
  251.             that the orientation of the line is constrained to the
  252.             nearest multiple of 15 degrees.  Use this if you want to
  253.             create perfect horizontal, vertical, or diagonal lines.
  254.           </p>
  255.               </dd>
  256.             </dl>
  257.           </div>
  258.         </div>
  259.         <div class="sect3" lang="en" xml:lang="en">
  260.           <div class="titlepage">
  261.             <div>
  262.               <div>
  263.                 <h4 class="title"><a id="gimp-tool-brush-options"></a>3.1.2.¬†
  264.       <span lang="en" xml:lang="en">Tool Options</span>
  265.     </h4>
  266.               </div>
  267.             </div>
  268.           </div>
  269.           <div class="figure">
  270.             <a id="id2627560"></a>
  271.             <p class="title">
  272.               <b>Figure¬†13.33.¬†
  273.         <span lang="en" xml:lang="en">Tool Options shared by all brush tools</span>
  274.       </b>
  275.             </p>
  276.             <div class="figure-contents">
  277.               <div class="mediaobject">
  278.                 <img src="../images/toolbox/tool-options-brushcommon.png" alt="Tool Options shared by all brush tools" />
  279.               </div>
  280.             </div>
  281.           </div>
  282.           <br class="figure-break" />
  283.           <p>
  284.       Many tool options are shared by several brush tools: these are described
  285.       here. Options that apply only to one specific tool, or to a small number
  286.       of tools, are described in the sections devoted to those tools.
  287.     </p>
  288.           <div class="variablelist">
  289.             <a id="gimp-tool-painting-modes"></a>
  290.             <p class="title">
  291.               <b>
  292.         <span lang="en" xml:lang="en">Paint Modes</span>
  293.       </b>
  294.             </p>
  295.             <dl>
  296.               <dt>
  297.                 <span class="term">Mode</span>
  298.               </dt>
  299.               <dd>
  300.                 <p>
  301.             The Mode drop-down list provides a selection of paint application
  302.             modes; a list of modes can be found in the glossary. As with the
  303.             opacity, the easiest way to understand what the Mode setting does
  304.             is to imagine that the paint is actually applied to a layer above
  305.             the layer you are working on, with the layer combination mode in
  306.             the Layers dialog set to the selected mode. You can obtain a great
  307.             variety of special effects in this way. The Mode option is only
  308.             usable for tools that can be thought of as adding color to the
  309.             image: the Pencil, Paintbrush, Airbrush, Ink, and Clone tools. For
  310.             the other brush tools, the option appears for the sake of
  311.             consistency but is always grayed out.
  312.           </p>
  313.                 <p>
  314.             In this list, some modes are particular:
  315.           </p>
  316.                 <div class="itemizedlist">
  317.                   <ul type="disc">
  318.                     <li>
  319.                       <p>
  320.                         <span class="guilabel">Dissolve</span>
  321.                       </p>
  322.                       <div class="figure">
  323.                         <a id="id2627664"></a>
  324.                         <p class="title">
  325.                           <b>Figure¬†13.34.¬†
  326.                   <span lang="en" xml:lang="en">Dissolve mode example</span>
  327.                 </b>
  328.                         </p>
  329.                         <div class="figure-contents">
  330.                           <div class="mediaobject">
  331.                             <img src="../images/toolbox/dissolve-mode-example.png" alt="Dissolve mode example" />
  332.                             <div class="caption">
  333.                               <p>
  334.                       Two brush-strokes made with the Airbrush, using the same
  335.                       fuzzy circular brush. Left: Normal mode. Right: Dissolve
  336.                       mode.
  337.                     </p>
  338.                             </div>
  339.                           </div>
  340.                         </div>
  341.                       </div>
  342.                       <br class="figure-break" />
  343.                       <p>
  344.                 For any paint tool with  opacity less than 100%, this very
  345.                 useful mode doesn't draw transparency but determines the
  346.                 probability of applying paint. This gives nice patterns of
  347.                 dots to paint-strokes or filling.
  348.               </p>
  349.                       <div class="figure">
  350.                         <a id="id2627713"></a>
  351.                         <p class="title">
  352.                           <b>Figure¬†13.35.¬†
  353.                   <span lang="en" xml:lang="en">Painting in Dissolve mode</span>
  354.                 </b>
  355.                         </p>
  356.                         <div class="figure-contents">
  357.                           <div class="mediaobject">
  358.                             <img src="../images/toolbox/mode-dissolve.png" alt="Painting in Dissolve mode" />
  359.                             <div class="caption">
  360.                               <p>
  361.                       This image has only the background layer and no Alpha
  362.                       channel. The background color is sky blue. Three
  363.                       strokes with Pencil and various opacities: 100%, 50%,
  364.                       25%. Foreground color pixels are scattered along
  365.                       brushstroke.
  366.                     </p>
  367.                             </div>
  368.                           </div>
  369.                         </div>
  370.                       </div>
  371.                       <br class="figure-break" />
  372.                     </li>
  373.                     <li>
  374.                       <p>
  375.                         <span class="guilabel">Behind</span>
  376.                       </p>
  377.                       <a id="id2627769" class="indexterm"></a>
  378.                       <a id="id2627782" class="indexterm"></a>
  379.                       <div class="figure">
  380.                         <a id="id2627794"></a>
  381.                         <p class="title">
  382.                           <b>Figure¬†13.36.¬†
  383.                   <span lang="en" xml:lang="en">
  384.                     Example for layer mode ‚Äú<span class="quote">Behind</span>‚Äù
  385.                   </span>
  386.                 </b>
  387.                         </p>
  388.                         <div class="figure-contents">
  389.                           <div class="mediaobject">
  390.                             <img src="../images/glossary/modes-normal2.png" alt="Example for layer mode Behind" />
  391.                           </div>
  392.                           <div class="mediaobject">
  393.                             <img src="../images/glossary/modes-behind.png" alt="Example for layer mode Behind" />
  394.                           </div>
  395.                         </div>
  396.                       </div>
  397.                       <br class="figure-break" />
  398.                       <p>
  399.                 This mode applies paint only to transparent areas of the
  400.                 layer: the lower the opacity, the more paint is applied.
  401.                 Thus, painting opaque areas has no effect; painting
  402.                 transparent areas has the same effect as normal mode. The
  403.                 result is always an increase in opacity. Of course none of
  404.                 this is meaningful for layers that lack an alpha channel.
  405.               </p>
  406.                       <p>
  407.                 In the above example image, Wilber is on the top layer,
  408.                 surrounded by transparency. The lower layer is solid light
  409.                 blue. The Bucket Fill tool was used, with the
  410.                 <span class="guilabel">Fill Whole Selection</span> option checked
  411.                 and the entire layer was selected. A pattern was used to
  412.                 paint with the Bucket Fill tool.
  413.               </p>
  414.                       <div class="figure">
  415.                         <a id="id2627869"></a>
  416.                         <p class="title">
  417.                           <b>Figure¬†13.37.¬†
  418.                   <span lang="en" xml:lang="en">
  419.                     Painting in ‚Äú<span class="quote">Behind</span>‚Äù mode
  420.                   </span>
  421.                 </b>
  422.                         </p>
  423.                         <div class="figure-contents">
  424.                           <div class="mediaobject">
  425.                             <img src="../images/toolbox/mode-behind.png" alt="Painting in Behind mode" />
  426.                             <div class="caption">
  427.                               <p>
  428.                       This image has two layers. The upper layer is active.
  429.                       Three brushtrokes with pencil, red color at 100%, 50%,
  430.                       25% : only transparent or semi-transparent pixels of
  431.                       the layer are painted.
  432.                     </p>
  433.                             </div>
  434.                           </div>
  435.                         </div>
  436.                       </div>
  437.                       <br class="figure-break" />
  438.                     </li>
  439.                     <li>
  440.                       <p>
  441.                         <span class="guilabel">Color Erase</span>
  442.                       </p>
  443.                       <a id="id2627928" class="indexterm"></a>
  444.                       <a id="id2627942" class="indexterm"></a>
  445.                       <div class="figure">
  446.                         <a id="id2627953"></a>
  447.                         <p class="title">
  448.                           <b>Figure¬†13.38.¬†
  449.                   <span lang="en" xml:lang="en">
  450.                     Example for layer mode ‚Äú<span class="quote">Color erase</span>‚Äù
  451.                   </span>
  452.                 </b>
  453.                         </p>
  454.                         <div class="figure-contents">
  455.                           <div class="mediaobject">
  456.                             <img src="../images/glossary/modes-normal2.png" alt="Example for layer mode Color erase" />
  457.                           </div>
  458.                           <div class="mediaobject">
  459.                             <img src="../images/glossary/modes-colorerase.png" alt="Example for layer mode Color erase" />
  460.                           </div>
  461.                         </div>
  462.                       </div>
  463.                       <br class="figure-break" />
  464.                       <p>
  465.                 This mode erases the foreground color, replacing it with
  466.                 partial transparency. It acts like the
  467.                 <a class="link" href="plug-in-colortoalpha.html" title="11.36.¬† Color to Alpha">Color to Alpha</a>
  468.                 filter, applied to the area under the brushstroke. Note that
  469.                 this only works on layers that possess an alpha channel;
  470.                 otherwise, this mode is identical to Normal.
  471.               </p>
  472.                       <p>
  473.                 In the above example image, the color of the Bucket Fill tool
  474.                 was white, so white parts of Wilber were erased and the blue
  475.                 background shows through.
  476.               </p>
  477.                       <div class="figure">
  478.                         <a id="id2628028"></a>
  479.                         <p class="title">
  480.                           <b>Figure¬†13.39.¬†
  481.                   <span lang="en" xml:lang="en">
  482.                     Painting in ‚Äú<span class="quote">Color Erase</span>‚Äù mode
  483.                   </span>
  484.                 </b>
  485.                         </p>
  486.                         <div class="figure-contents">
  487.                           <div class="mediaobject">
  488.                             <img src="../images/toolbox/mode-erase.png" alt="Painting in Color Erase mode" />
  489.                             <div class="caption">
  490.                               <p>
  491.                       This image has only one layer, the background layer.
  492.                       Background color is sky blue. Three brushtrokes with
  493.                       pencil:
  494.                     </p>
  495.                               <div class="orderedlist">
  496.                                 <ol type="1">
  497.                                   <li>
  498.                                     <p>
  499.                           With the exact color of the blue area: only this
  500.                           blue color is erased.
  501.                         </p>
  502.                                   </li>
  503.                                   <li>
  504.                                     <p>
  505.                           With the exact color of the red area. Only this
  506.                           red color is erased, whatever its transparency.
  507.                           Erased areas are made transparent.
  508.                         </p>
  509.                                   </li>
  510.                                   <li>
  511.                                     <p>
  512.                           With the sky blue color of the layer background:
  513.                           only this color is erased.
  514.                         </p>
  515.                                   </li>
  516.                                 </ol>
  517.                               </div>
  518.                             </div>
  519.                           </div>
  520.                         </div>
  521.                       </div>
  522.                       <br class="figure-break" />
  523.                     </li>
  524.                   </ul>
  525.                 </div>
  526.               </dd>
  527.               <dt>
  528.                 <span class="term">Opacity</span>
  529.               </dt>
  530.               <dd>
  531.                 <a id="id2628131" class="indexterm"></a>
  532.                 <a id="id2628146" class="indexterm"></a>
  533.                 <p>
  534.             The Opacity slider sets the transparency level for the brush
  535.             operation. To understand how it works, imagine that instead of
  536.             altering the active layer, the tool creates a transparent layer
  537.             above the active layer and acts on that layer. Changing Opacity in
  538.             the Tool Options has the same effect that changing opacity in the
  539.             Layers dialog would have in the latter situation. It controls the
  540.             ‚Äú<span class="quote">strength</span>‚Äù
  541.             of all brush tools, not just those that paint on the active layer.
  542.             In the case of the Eraser, this can come across as a bit
  543.             confusing: it works out that the higher the ‚Äú<span class="quote">opacity</span>‚Äù
  544.             is, the more transparency you get.
  545.           </p>
  546.               </dd>
  547.               <dt>
  548.                 <span class="term">Brush</span>
  549.               </dt>
  550.               <dd>
  551.                 <p>
  552.             The brush determines how much of the image is affected by the tool,
  553.             and how it is affected, when you trace out a brushstroke with the
  554.             pointer. GIMP allows you to use several different types of brushes,
  555.             which are described in the
  556.             <a class="link" href="gimp-concepts-brushes.html" title="6.¬† Brushes">Brushes</a>
  557.             section. The same brush choices are available for all brush tools
  558.             except the Ink tool, which uses a unique type of procedurally
  559.             generated brush. The colors of a brush only come into play for tools
  560.             where they are meaningful: the Pencil, Paintbrush, and Airbrush
  561.             tools. For the other brush tools, only the intensity distribution of
  562.             a brush is relevant.
  563.           </p>
  564.               </dd>
  565.               <dt>
  566.                 <span class="term">Scale</span>
  567.               </dt>
  568.               <dd>
  569.                 <p>
  570.             This option lets you to modify precisely the size of the brush.
  571.             You can use the arrow keys to vary by ¬±0.01 or the Page-Up and
  572.             Page-Down keys to vary by ¬±0.05.
  573.           </p>
  574.               </dd>
  575.               <dt>
  576.                 <span class="term">Pressure Sensitivity</span>
  577.               </dt>
  578.               <dd>
  579.                 <p>
  580.             The Pressure Sensitivity section is only meaningful if you are
  581.             using a tablet:  it allows you to decide which aspects of the
  582.             tool's action should be affected by how hard you press the stylus
  583.             against the tablet.  The possibilities are
  584.             <span class="guilabel">opacity</span>, <span class="guilabel">hardness</span>,
  585.             <span class="guilabel">rate</span>, <span class="guilabel">size</span>, and
  586.             <span class="guilabel">color</span>.  They  work together:  you can enable
  587.             as many of them as you like.
  588.             For each tool, only the ones that are meaningful are listed.
  589.             Here is what they do:
  590.           </p>
  591.                 <div class="variablelist">
  592.                   <dl>
  593.                     <dt>
  594.                       <span class="term">Opacity</span>
  595.                     </dt>
  596.                     <dd>
  597.                       <p>
  598.                   The effect of this option is described above.
  599.                 </p>
  600.                     </dd>
  601.                     <dt>
  602.                       <span class="term">Hardness</span>
  603.                     </dt>
  604.                     <dd>
  605.                       <p>
  606.                   This option applies to brushes with fuzzy edges. If it is
  607.                   enabled, the harder you press, the darker the fuzzy parts of
  608.                   the brush will appear.
  609.                 </p>
  610.                     </dd>
  611.                     <dt>
  612.                       <span class="term">Rate</span>
  613.                     </dt>
  614.                     <dd>
  615.                       <p>
  616.                   This option applies to the Airbrush, Convolve tool, and
  617.                   Smudge tool, all of which have time-based effects. Pressing
  618.                   harder makes these tools act more rapidly.
  619.                 </p>
  620.                     </dd>
  621.                     <dt>
  622.                       <span class="term">Size</span>
  623.                     </dt>
  624.                     <dd>
  625.                       <p>
  626.                   This option applies to all of the pressure sensitive brush
  627.                   tools. If the option is checked, then pressing harder will
  628.                   increase the size of the area affected by the brush.
  629.                 </p>
  630.                     </dd>
  631.                     <dt>
  632.                       <span class="term">Color</span>
  633.                     </dt>
  634.                     <dd>
  635.                       <p>
  636.                   This option only applies to the painting tools: the Pencil,
  637.                   Paintbrush, and Airbrush; and only if you are using colors
  638.                   from a gradient. If these conditions are met, then pressing
  639.                   harder causes colors to be taken from higher in the
  640.                   gradient.
  641.                 </p>
  642.                     </dd>
  643.                   </dl>
  644.                 </div>
  645.               </dd>
  646.               <dt>
  647.                 <span class="term">Fade Out</span>
  648.               </dt>
  649.               <dd>
  650.                 <p>
  651.             This option causes each stroke to fade out over the specified
  652.             distance. It is easiest to visual for painting tools, but applies
  653.             to all of the brush tools. It is equivalent to gradually reducing
  654.             the opacity along the trajectory of the stroke. Note that, if you
  655.             are using a tablet, this option does not change the effects of
  656.             brush pressure.
  657.           </p>
  658.               </dd>
  659.               <dt>
  660.                 <span class="term">Apply Jitter</span>
  661.               </dt>
  662.               <dd>
  663.                 <a id="id2628450" class="indexterm"></a>
  664.                 <p>
  665.             You know ‚Äú<span class="quote">spacing</span>‚Äù in brush strokes: strokes are
  666.             made of successive brush marks which, when they are very near,
  667.             seem to draw a continuous line. Here, instead of being aligned
  668.             brush marks are scattered over a distance you can set with the
  669.             <span class="guimenuitem">Quantity</span> slider.
  670.           </p>
  671.                 <div class="figure">
  672.                   <a id="id2628479"></a>
  673.                   <p class="title">
  674.                     <b>Figure¬†13.40.¬†
  675.               <span lang="en" xml:lang="en">‚Äú<span class="quote">Jitter</span>‚Äù example</span>
  676.             </b>
  677.                   </p>
  678.                   <div class="figure-contents">
  679.                     <div class="mediaobject">
  680.                       <img src="../images/menus/jitter.png" alt="Jitter example" />
  681.                       <div class="caption">
  682.                         <p>
  683.                   From top to bottom: without jitter, jitter = 1, jitter = 4.
  684.                 </p>
  685.                       </div>
  686.                     </div>
  687.                   </div>
  688.                 </div>
  689.                 <br class="figure-break" />
  690.               </dd>
  691.               <dt>
  692.                 <span class="term">Incremental</span>
  693.               </dt>
  694.               <dd>
  695.                 <p>
  696.             The Incremental check-box activates incremental mode for the tool.
  697.             If it is deactivated, the maximum effect of a single stroke is
  698.             determined by the opacity, and moving the brush repeatedly over
  699.             the same spot will not increase the effect beyond this limit. If
  700.             Incremental is active, each additional pass with the brush will
  701.             increase the effect, but the opacity can't exceed the opacity set
  702.             for the tool. This option is available for all brush tools except
  703.             those which have a ‚Äú<span class="quote">rate</span>‚Äù
  704.             control, which automatically implies an incremental effect. See
  705.             also <a class="xref" href="gimp-concepts-layer-modes.html" title="2.¬† Layer Modes">Section¬†2, ‚Äú
  706.     <span lang="en" xml:lang="en">Layer Modes</span>
  707.   ‚Äù</a>.
  708.           </p>
  709.               </dd>
  710.               <dt>
  711.                 <a id="gimp-tool-painting-gradient"></a>
  712.                 <span class="term">Color from Gradient</span>
  713.               </dt>
  714.               <dd>
  715.                 <div class="figure">
  716.                   <a id="id2628573"></a>
  717.                   <p class="title">
  718.                     <b>Figure¬†13.41.¬†
  719.               <span lang="en" xml:lang="en">Gradient options for painting tools.</span>
  720.             </b>
  721.                   </p>
  722.                   <div class="figure-contents">
  723.                     <div class="mediaobject">
  724.                       <img src="../images/toolbox/tool-options-paint-gradient.png" alt="Gradient options for painting tools." />
  725.                     </div>
  726.                   </div>
  727.                 </div>
  728.                 <br class="figure-break" />
  729.                 <p>
  730.             Instead of using the foreground color (as shown in the Color Area
  731.             of the Toolbox), by checking the "Use color from gradient" option
  732.             you can choose to paint with a gradient, giving colors that change
  733.             gradually along the brush trajectory. For basic information on
  734.             gradients, see the
  735.             <a class="link" href="gimp-concepts-gradients.html" title="10.¬† Gradients">Gradients</a> section.
  736.           </p>
  737.                 <p>
  738.             You have several options to control what gradient is used and how
  739.             it is laid out:
  740.           </p>
  741.                 <div class="variablelist">
  742.                   <dl>
  743.                     <dt>
  744.                       <span class="term">Gradient</span>
  745.                     </dt>
  746.                     <dd>
  747.                       <p>
  748.                   Here you see a display of the current gradient. Clicking on
  749.                   it brings up a Gradient Selector, which will allow you to
  750.                   choose a different gradient.
  751.                 </p>
  752.                     </dd>
  753.                     <dt>
  754.                       <span class="term">Reverse</span>
  755.                     </dt>
  756.                     <dd>
  757.                       <p>
  758.                   Normally a brushstroke starts with colors from the left side
  759.                   of the gradient, and progresses rightward. If "Reverse" is
  760.                   checked, the stroke starts with colors from the right side,
  761.                   and progresses leftward.
  762.                 </p>
  763.                     </dd>
  764.                     <dt>
  765.                       <span class="term">Length</span>
  766.                     </dt>
  767.                     <dd>
  768.                       <p>
  769.                   This option sets the distance corresponding to one complete
  770.                   cycle through the gradient colors. The default units are
  771.                   pixels, but you can choose a different unit from the
  772.                   adjoining Units menu.
  773.                 </p>
  774.                     </dd>
  775.                     <dt>
  776.                       <span class="term">Repeat</span>
  777.                     </dt>
  778.                     <dd>
  779.                       <div class="figure">
  780.                         <a id="id2628707"></a>
  781.                         <p class="title">
  782.                           <b>Figure¬†13.42.¬†
  783.                     <span lang="en" xml:lang="en">
  784.                       Illustration of the effects of the three gradient-repeat
  785.                       options, for the ‚Äú<span class="quote">Abstract 2</span>‚Äù gradient.
  786.                     </span>
  787.                   </b>
  788.                         </p>
  789.                         <div class="figure-contents">
  790.                           <div class="mediaobject">
  791.                             <img src="../images/tool-options/brush-gradient-normal.png" alt="Illustration of the effects of the three gradient-repeat options, for the Abstract 2 gradient." />
  792.                             <div class="caption">
  793.                               <p>Abstract2 Gradient</p>
  794.                             </div>
  795.                           </div>
  796.                           <div class="mediaobject">
  797.                             <img src="../images/tool-options/brush-gradient-none.png" alt="Illustration of the effects of the three gradient-repeat options, for the Abstract 2 gradient." />
  798.                             <div class="caption">
  799.                               <p>None</p>
  800.                             </div>
  801.                           </div>
  802.                           <div class="mediaobject">
  803.                             <img src="../images/tool-options/brush-gradient-sawtooth.png" alt="Illustration of the effects of the three gradient-repeat options, for the Abstract 2 gradient." />
  804.                             <div class="caption">
  805.                               <p>Sawtooth</p>
  806.                             </div>
  807.                           </div>
  808.                           <div class="mediaobject">
  809.                             <img src="../images/tool-options/brush-gradient-triangular.png" alt="Illustration of the effects of the three gradient-repeat options, for the Abstract 2 gradient." />
  810.                             <div class="caption">
  811.                               <p>Triangular</p>
  812.                             </div>
  813.                           </div>
  814.                         </div>
  815.                       </div>
  816.                       <br class="figure-break" />
  817.                       <p>
  818.                   This option determines what happens if a brushstroke extends
  819.                   farther than the Length specified above. There are three
  820.                   possibilities: "None" means that the color from the end of
  821.                   the gradient will be used throughout the remainder of the
  822.                   stroke; "Sawtooth wave" means that the gradient will be
  823.                   restarted from the beginning, which will often produce a
  824.                   color discontinuity; "Triangular wave" means that the
  825.                   gradient will be traversed in reverse, afterwards bouncing
  826.                   back and forth until the end of the brushstroke.
  827.                 </p>
  828.                     </dd>
  829.                   </dl>
  830.                 </div>
  831.               </dd>
  832.             </dl>
  833.           </div>
  834.         </div>
  835.         <div class="sect3" lang="en" xml:lang="en">
  836.           <div class="titlepage">
  837.             <div>
  838.               <div>
  839.                 <h4 class="title"><a id="id2628851"></a>3.1.3.¬†
  840.       <span lang="en" xml:lang="en">Further Information</span>
  841.     </h4>
  842.               </div>
  843.             </div>
  844.           </div>
  845.           <p>
  846.       Advanced users may be interested to know that brush tools actually
  847.       operate at a sub-pixel level, in order to avoid producing jagged-looking
  848.       results. One consequence of this is that even if you work with a
  849.       hard-edged brush, such as one of the Circle brushes, pixels on the edge
  850.       of the brushstroke will only be partially affected. If you need to have
  851.       all-or-nothing effects (which may be necessary for getting a good
  852.       selection, or for cutting and pasting, or for operating pixel-by-pixel
  853.       at a high zoom level), use the Pencil tool, which makes all brushes
  854.       perfectly hard and disables sub-pixel anti-aliasing.
  855.     </p>
  856.         </div>
  857.       </div>
  858.     </div>
  859.     <div class="navfooter">
  860.       <hr />
  861.       <table width="100%" summary="Navigation footer">
  862.         <tr>
  863.           <td width="40%" align="left"><a accesskey="p" href="gimp-tool-foreground-select.html"><img src="../images/prev.png" alt="Prev" /></a>¬†</td>
  864.           <td width="20%" align="center">
  865.             <a accesskey="u" href="gimp-toolbox.html">
  866.               <img src="../images/up.png" alt="Up" />
  867.             </a>
  868.           </td>
  869.           <td width="40%" align="right">¬†<a accesskey="n" href="gimp-tool-painting.html"><img src="../images/next.png" alt="Next" /></a></td>
  870.         </tr>
  871.         <tr>
  872.           <td width="40%" align="left" valign="top"><a accesskey="p" href="gimp-tool-foreground-select.html">2.8.¬†
  873.     <span lang="en" xml:lang="en">Foreground Select</span>
  874.   </a>¬†</td>
  875.           <td width="20%" align="center">
  876.             <a accesskey="h" href="index.html">
  877.               <img src="../images/home.png" alt="Home" />
  878.             </a>
  879.           </td>
  880.           <td width="40%" align="right" valign="top">¬†<a accesskey="n" href="gimp-tool-painting.html">3.2.¬†
  881.     <span lang="en" xml:lang="en">Painting Tools (Pencil, Paintbrush, Airbrush)</span>
  882.   </a></td>
  883.         </tr>
  884.       </table>
  885.     </div>
  886.   </body>
  887. </html>
  888.