i dye and paint most, if not all, of the fabric that i use in the quilts that i sell.
most mass market fabric and patterns have copyright laws and now with ebay, etsy, and other online sales the fabric designers have been asking for part of the profits.
its just best to avoid all of these problems by using your original fabric and your original patterns. the only works that are from patterns that are allowed to be sold are ones that are in public domain because they date before the copyright laws or the copyright has expired.
the only thing i don't like about the process is the mess. i do all this work in my garage and the floor looks like a pollock painting.