Freehand & Brush Tool - Create Brush

Click this button to create a new brush shape from the selected objects. The new brush is added to the Select Brush list on the Freehand & Brush Tool Infobar
and Brush strokes in the Line Gallery.

Please note: if you wish to create a brush from an object that has a Live Effect on it, you must first lock the effect before creating the brush. Otherwise the brush will just take the form of the underlying shape. Find out more about locked vs Live Effects.

For more information see Creating a brush.