There are 3 brushes in adult kits and 2 brushes in kids kits. It is not necessary to purchase additional brushes, however some of our customers do choose to purchase additional brushes to avoid the need to wait for brushes to dry after cleaning.
Also another food for thought: there are so many different shapes, sizes and types of paintbrushes when going into an art store. Don't be overwhelmed! There is no need to rush out and buy all kinds, it is a good idea to do your research and see how go with the included brushes first.