Abstract: In a brush cap for protecting a hair bundle of a cosmetic and/or paint or artist's brush, in order to obtain a more flexible application also for a plurality of brushes or for different brush shapes, and for the purpose of broadening the range of application of the brush cap, it is provided that a second end of the brush cap, through which a brush shaft, given proper use of the brush cap, projects, is configured such that it is radially expandable.