A brush
is a pixmap or set of pixmaps used for painting. GIMP includes a set of
10 “paint tools”, which not only perform operations that you
would normally think of as painting, but also operations such as erasing,
copying, smudging, lightening or darkening, etc. All of the paint tools,
except the ink tool, use the same set of brushes. The brush pixmaps
represent the marks that are made by single “touches” of the
brush to the image. A brush stroke, usually made by moving the pointer
across the image with the mouse button held down, produces a series of
marks spaced along the trajectory, in a way specified by the
characteristics of the brush and the paint tool being used.
Brushes can be selected by clicking on an icon in the
Brushes dialog. GIMP's
current brush is shown in the
Brush/Pattern/Gradient area of the Toolbox. Clicking on the brush
symbol there is one way of activating the Brushes dialog.
When you install GIMP, it comes with a number of basic
brushes, plus a few bizarre ones that serve mainly to give you examples of
what is possible (i. e., the "green pepper" brush in the illustration).
You can also create new brushes, or download them and install them so that
GIMP will recognize them.
GIMP can use several different types of brushes. All of them, however, are
used in the same way, and for most purposes you don't need to worry about
the differences when you paint with them. Here are the available types of
brushes:
-
Ordinary brushes
-
Most of the brushes supplied with GIMP fall into this category. They
are represented in the Brushes dialog by grayscale pixmaps. When you
paint using them, the current foreground color (as shown in the
Color Area of the Toolbox) is substituted for black, and the pixmap
shown in the brushes dialog represents the mark that the brush makes
on the image.
To create such a brush: Create a small image in gray levels using
zoom. Save it with the .gbr extension. Click on Refresh button in
the Brush Dialog to get it in preview without it being necessary to
restart GIMP.
-
Color brushes
-
Brushes in this category are represented by colored images in the
Brushes dialog. They can be pictures or text. When you paint with
them, the colors are used as shown; the current foreground color
does not come into play. Otherwise they work the same way as
ordinary brushes.
To create such a brush: Create a small RGBA image. For this, open
New Image, select RGB for image type and Transparent for fill type.
Draw your image and and firs save it as a .xcf file to keep its
properties. Then save it in .gbr format. Click
on the Refresh button in Brush Dialog to get
your brush without it being necessary to restart GIMP.
![[Tip]](images/tip.png)
|
Tip |
|
When you do a Copy or a Cut on a selection, you see the contents
of the clipboard (that is the selection) at the first position in
the brushes dialog. And you can use it for painting.
|
-
Image hoses / Image pipes
-
Brushes in this category can make more than one kind of mark on an
image. They are indicated by small red triangles at the lower right
corner of the brush symbol in the Brushes dialog. They are sometimes
called "animated brushes" because the marks change as you trace out
a brushstroke. In principle, image hose brushes can be very
sophisticated, especially if you use a tablet, changing shape as a
function of pressure, angle, etc. These possibilities have never
really been exploited, however; and the ones supplied with GIMP are
relatively simple (but still quite useful).
You will find an example on how to create such brushes in
Animated brushes
-
Parametric brushes
-
These are brushes created using the
Brush Editor, which
allows you to generate a wide variety of brush shapes by using a
simple graphical interface. A nice feature of parametric brushes
is that they are resizable. It is possible,
using the dialog, to make key
presses or mouse wheel rotations cause the current brush to
become larger or smaller, if it is a parametric brush.
Now, all brushes have a variable size. In fact, in the option box of all
painting tools there is a slider to enlarge or reduce the size of the
active brush. You can do this directly in the image window if you have
set correctly your mouse wheel; see
Varying brush size.
In addition to the brush pixmap, each GIMP brush has one other important
property: the brush Spacing.
This represents the distance between consecutive brush-marks when a
continuous brushstroke is painted. Each brush has an assigned default
value for this, which can be modified using the Brushes dialog.
