Units and Grids options
Document units The default unit of measurement in Expression Design is pixels, but you can instead use inches, centimeters, millimeters, picas, or points. This is the measurement system that appears in the rulers , Action Bar, and most other locations where measurements are specified.
Stroke units You can specify your stroke width in a measurement other than the default document units. For example, you might want Document units set to centimeters, but Stroke units set to pixels. This setting affects the Stroke Width slider in the Appearance section of the Properties panel.
Type units You can select the measurements to use when specifying type size and baseline offset. This can be helpful when you need your type size to fit a specific amount of space.
Grid size The default grid spacing (the distance between lines in the grid) is 36 points, but you can change it to any amount between .1 and 360 points.
Ruler origin is always top left of artboard By default, the document rulers are set so that their origins (the 0,0 point) is set in the top-left corner of the canvas. However, if you disable this option, Expression Design displays the 0,0 point in the lower-left corner of the document page whenever the Document Units options (see above) is set to anything other than pixels. When the Document Units option is set to Pixels, the ruler origin is always in the top-left corner. You can override this setting, placing the zero-point on the rulers wherever you want it to be, by choosing Set Document Origin from the File menu, and then clicking somewhere on the document frame.
Rotation steps When you rotate or drag an object with the SHIFT key held down, Expression Design constrains the rotation angle based on this value. For example, when this option is set to 8 (the default value), pressing the SHIFT key constrains the rotation to 45 degree angles (because 360 degrees divided by 8 equals 45).
Nudge increment When you press an arrow key on the keyboard, any selected object or node is moved (nudged) by the value in this field. You can specify any value from zero to 100 points. If you hold down the CTRL key while pressing an arrow key, Expression Design nudges by 1/10 of the Nudge increment. If you hold down the SHIFT key, it nudges by 10x the Nudge increment .
Stack gap size By default, the Stack features place objects about 8 points away from each other. However, you can select any value between -2000 and 2000 points. (Negative values will cause objects to overlap when stacked.)