All of my brushes are free to use for your personal, non-commercial use & are licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 Poland License.
If want to use them for commercial use, just contact me through contact page & we will finalize license proccess.
Non-commercial?
Use my brushes for your own artworks inside deviantart.com, for training/practicing skills on your PC/notebook. Please send me an info with link of your work & credit me with a nick (env1ro) & website (www.env1ro.deviantart.com).