post full pattern modified from one I paid for?

First, patterns themselves are not copyrighted. It’s the specific wording of the pattern and photographs that are copyrighted. So if you’ve taken the basics or starting points of a standard cable mitten pattern to inspire the creation of your own pattern, you’re well in the clear to publish your pattern - and to charge for it too if you’d like. It’s impossible not to reproduce at least some aspects of other patterns because there are only so many techniques! I’ve drafted a couple of my own and they have elements found in Lily France’s patterns, and hers have elements found in pre-50s patterns - because we drafted stuff from the same style movement, and there’s simply a finite number of knitting techniques to produce certain garments styles.

/r/knitting Thread