This is a great site for researching what you can and cannot do. http://www.copyright.gov/
As far as Tabberone goes she has a lot of useful info on her site but some of it is just a gray area in the actual law. I have never read the actual settlement agreement that she had regarding the fabric so who knows what it really states. I get a big laugh out of her Etsy section on the maids of misinformation. So true!
Original bottlecaps do not fall into this catagory as they are not a how to they are someones art.
I see people on Etsy trying to sell license rights to their patterns that you can basically buy anywhere. A knot dress is really a knot dress. Most of these people have no idea that a lawsuit would be costly and really just not worth it. You might be able to claim some damage if Walmart sells it but not a small crafter.
Just so everyone know they are trying to pass legislation to make designers own their patterns and dresses and things. Good luck.