User Guide

GNU Image Manipulation Program

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Figure 12.23: Dissolve mode example

Two brushstrokes made with the Airbrush, using the same fuzzy circular brush. Left: Normal mode. Right: Dissolve mode.

Dissolve In this very useful mode, for fuzzy brushes the gray level of the brush determines not the paint density, but rather

the probability of applying paint. This gives a nice way of creating rough-looking paintstrokes.

Gradient

Figure 12.24: Gradient options for painting tools.

Instead of using the foreground color (as shown in the Color Area of the Toolbox), by checking the "Use color from

gradient" option you can choose to paint with a gradient, giving colors that change gradually along the brush trajectory.

For basic information on gradients, see the Gradients section.

You have several options to control what gradient is used and how it is laid out:

Gradient Here you see a display of the current gradient. Clicking on it brings up a Gradient Selector, which will allow

you to choose a different gradient.

Reverse Normally a brushstroke starts with colors from the left side of the gradient, and progresses rightward. If "Reverse"

is checked, the stroke starts with colors from the right side, and progresses leftward.

Length This option sets the distance corresponding to one complete cycle through the gradient colors. The default units

are pixels, but you can choose a different unit from the adjoining Units menu.

Table 12.1: Illustration of the effects of the three gradient-repeat options, for the ‘Abstract 2’ gradient.

Abstract2

Gradient

None

Sawtooth

Triangular

Repeat This option determines what happens if a brushstroke extends farther than the Length speciﬁed above. There are

three possibilities: "None" means that the color from the end of the gradient will be used throughout the remainder of the

stroke; "Sawtooth wave" means that the gradient will be restarted from the beginning, which will often produce a color

discontinuity; "Triangular wave" means that the gradient will be traversed in reverse, afterwards bouncing back and forth

until the end of the brushstroke.