Customizing brush tips (Photoshop)
You can customize brush tips by editing their options and create new brush tip shapes by sampling pixels in an image. The brush tip you select determines the shape, diameter, and other characteristics of a brush mark.
Selection sampled to create a custom brush (left), and brush stroke using the custom brush (right)
To create a new brush tip shape:
- Use any selection tool to select a part of an image to use as a custom brush. Feather should be set to 0 pixels if you want to create a brush with a sharp edge. The brush shape can be up to 2500 pixels by 2500 pixels in size.
- Choose Edit > Define Brush Preset.
- Name the brush, and click OK.
If you want to define a brush with soft edges, select pixels with gray values. (Colored brush shapes appear as gray values.)
To lock brush tip shape attributes:
To lock a brush tip, click the unlock icon 
. To unlock the tip, click the lock icon 
.