Designs can't be subject to copyright, but expressions of a design can be - this generally means it's a breach of copyright to produce copies of an existing pattern, but it's fine to recreate it and sell your own version. (It's all about ideas vs artistic expression - you need to patent designs to protect them, copyright applies to artistic expression, so it's not for the design itself, but the artistic choices made to show a pattern, like fonts for the text etc, original wording / instructions, stuff like that).

Unless the patterns are in the public domain, anyway - then you can do whatever you like with them. 

Back home again, I have several tartan pattern books and the person/s selling copies has unusually similar furniture and other props for photos in my books. These books are copyright and the enhanced copies are 99% similar to photos in my books.
The books are about both technique and patterns.
The books have 140 patterns so selling at $8 each is a real little money earner $1,120 to be exact. As they might sell multiples of some styles then the profit is endless.
I think I wasted my time getting my account up to date so I could sell on ebay again.