ArtRage Studio Pro provides a range of painting tools designed to work like their real world counterparts...
Among the top 10 Mac apps in Top Grossing list of photography category in the US...
Painter 2015 authentic natural-media paint program for Mac.
Unfortunately, there is no user's guide available for this application. The official website doesn't offer any downloadable files, but you have the possibility to use the ticketing system to open a ticket with this request. If the developer has a user's guide, he should provide it to you on the request ticket that you will need to open.