Image with four guides
In addition to the image grid, GIMP also gives you a more flexible
type of positioning aid: guides. These are
horizontal or vertical lines that you create by clicking on one of
the rulers and dragging into the image. You can create as many
guides as you like, positioned wherever you like. To move a guide
after you have created it, activate the Move tool in the Toolbox (or
press the M key), you can then click and drag a
guide. To delete a guide, simply drag it outside the image. Holding
down the Shift key, you can move everything but a guide, using the
guides as an effective alignment aid.
As with the grid, you can cause the pointer to snap to nearby
guides, by toggling
in the image menu. If you have a number of guides and they are
making it difficult for you to judge the image properly, you can
hide them by toggling
It is suggested that you only do this momentarily, otherwise you
may get confused the next time you try to create a guide and
don't see anything happening.
If it makes things easier for you, you can change the default behavior
for guides in the
Appearance page of the Preferences dialog. Disabling "Show
guides" is probably a bad idea, though, for the reason just given.
Another use for guides: the Guillotine plugin can use guides
to slice an image into a set of sub-images.
See also Guides in Glossary.