There are patterns being sold on Etsy and elsewhere for all sorts of designs and things, not just clothing. The arguments presented on the link above apply clearly to sewing patterns to create garments, and I would also imagine a similar logic would apply to patterns to create other utilitarian items -- e.g. crochet hats, knitted socks, etc.
However, if you create a pattern for a sweater or other object that has an original design of say, a Scotsman playing a bagpipe, the charted Scotsman design IS covered by copyright and a purchaser of the pattern cannot go and sell finished sweaters with the knitted Scotsman. They could recreate and sell the basic sweater made from the pattern as long as the Scotsman design was NOT incorporated into the item.
So for my quilt designs -- No one can prohibit people from making and selling items made from a traditional quilt design (such as shoo-fly, 9 patch, drunkard's path, etc.), because these are in the public domain.
However, if a designer creates a design which is original and unique, such as my version of an edelweiss blossom or a raccoon, then that specific design is covered by copyright and cannot be rightfully reproduced and sold without permission from the original designer.
