This section continues the explanation given in Gradient Fill and also gives some examples.
In the Gradient box you can choose the basic colors for the gradient. The default gradient is FG to BG RGB (Red, Green, Blue) mode, followed by FG to BG HSB (Hue, Saturation, Brightness) mode. Both of these produce a gradient that runs from the foreground color through to the background color, blending the tones in between. The next option, Foreground to transparent, produces a gradient in which the foreground color gradually thins out. These three gradients all use the current foreground and background colors to produce their effects.
There are many other gradients, most of which, like German Flag and French Flag, generate colors independently of the current foreground and background.
In the Gradient type box you can choose a shape or style for the gradient. The default type is Linear, which draws the gradient in a straight direction across a plane. The other options include Radial, Spiral Clockwise and Anti-Clockwise, Square, Conical Symmetric and Asymmetric, and BiLinear. Each of these defines a style for the gradient. For instance, if you select one of the spiral options and drag the pointer a short way across an image, a tight spiral will be drawn, of course using the currently selected gradient. If you drag the pointer a greater distance the spiral will be much wider. The same general principle goes for all the other gradient types. For instance, if you use the gradient FG to BG RGB (Red, Green, Blue) mode with the Linear type, the foreground and background colors will form solid blocks before and after the start and finish points respectively.
In the Mode box you determine how the gradient will be blended with the existing image. The default is Normal. There are many others, including Dissolve, Multiply and Luminosity. The best way to get to know how the modes work is to experiment. There is more explanation and some examples in Brush modes. Two things worth remembering are: the mode used with the gradient is permanent once applied and can only be undone by using Undo from the Edit menu; in most cases the gradient will cover the existing image if the Opacity is set at 100%.
In the Opacity box you can choose the transparency of the gradient. The default is 100% opaque (or 0% transparent). As said above, you need to reduce the opacity from 100% in order to see the existing image show through the applied gradient. Remember that the effect of applying a gradient with an opacity is permanent and can only be undone by selecting Undo from the Edit menu.
The gradient is always applied by dragging the pointer and then releasing the mouse. Different gradients will take longer or shorter periods of time to be take effect. All in all the final effect depends on the combination of settings made in the Gradient, Gradient type, Mode and Opacity boxes.
Using these settings:
this gradient can be produced:
See: