1. A method, comprising: using a computer to perform: receiving user input representing a brush stroke made by a brush tool of an image editing program sweeping across a canvas, wherein the brush tool comprises a plurality of bristles; and generating a vector representation of the effects of the brush stroke; wherein said generating a vector representation of the effects of the brush stroke comprises: for each of the plurality of bristles: determining a path along which the bristle has swept; and generating a vector representation of the path along which the bristle has swept; and wherein the vector representation of the effects of the brush stroke comprises the vector representations of the paths along which each of the plurality of bristles has swept.