Portal & Half-Life Brush Set
A brush set with both Portal and Half-Life themed brushes in it.
These brushes are free to use.
I made some of the brushes, but some are others great work.
Working Link!!: http://iaa33.deviantart.com/art/Portal-and-Half-Life-Brush-Set-286447033
Sorry I cant seem to get Brusheezy to make the file work.
Valve owns both of these games