Artweaver is an amazing program for digital painting and more. You can still get the free version or upgrade to the ArtweaverPlus version really cheaply. This is a very good digital art software package that just keeps on getting better. If you are on a tight budget, or want an alternative to the Big Name software, take a look at this software, give a try and see for yourself. We still use it a lot, and it plays nicely with Photoshop.
