You can create a custom brush from scratch using a raster image, from a copied preset or from a pixel selection.
To create a custom preset brush stroke from scratch:
On the Brushes panel, click Panel Preferences and then select:
New Intensity Brush—creates a brush stroke using a raster image, with darker pixels from the image rendered more opaque and lighter pixels more transparent. In the pop-up dialog, navigate to and select a file, and click Open.
New Round Brush—creates a brush stroke based on a circular shape.
New Square Brush—creates a brush stroke based on a rectangular shape.
New Image Brush—creates a brush stroke based on the color values of a raster image. In the pop-up dialog, navigate to and select a file, and click Open.
The new brush is added to the selected category using default settings. To edit the default settings, follow the procedure below from step 3 immediately below.
To create a custom preset brush stroke from a preset:
On the Brushes panel, select a brush and click Edit Brush.
In the dialog, click Duplicate and then Close.
Select the new brush at the bottom of the panel and click Edit Brush again.
Adjust the settings in the dialog. See Modifying brushes for more information.
Click Close.
To create a custom image brush from a pixel selection:
Make a selection using a pixel selection tool.
On the Brushes panel, choose a category to save your brush to.
click Panel Preferences and then select New Brush From Selection.
The image brush is added to the end of the current brush category. Custom intensity brushes can also be created from a mask layer that has a pixel selection in place by using the same process.
To create a multi-brush:
On the Brushes panel, create a main brush or duplicate a selected brush.
Select the new brush and click Edit Brush.
Click the Sub Brushes tab.
Click Add Bitmap, select a nib file for your sub brush and click Open.
Double-click the brush entry appearing in the window to launch the Sub-Brush Editor.
Edit the sub brush settings as you would for your base brush, then click Close.
In the Brush Editing dialog, change sub brush settings to control:
Drawing—controls where the sub brush is drawn in relation to the main brush.
Blending—controls how the sub brush blends with the main brush.
Sync size—when checked, sets the default width of the stroke to match that of the main brush.
Sync spacing—when checked, sets the distance between each nozzle point to match that of the main brush.