A lot of the quilts I see are just color variation of some well known blocks and stitched or combined blocks. I don't think a log cabin block could be patented even if has a unusual distribution of colors or fabrics. All of the blocks that I see are just very old designs or just using different colors.. Could twisting and turning or using different colors in a block be patented? Who would own the Log Cabin design? I can see where printed directions that come with some patterns could be patented because I'm sure Grandmother did not get a patent for the directions for the log cabin.
If something is patented, you can go online at the to see if it actually has a patent on it. Just go to the Smithsonian's website and look the patent up. If it's not there, it doesn't have a patent. If the patent number is not on the printed directions, it probably is not patented.
This is a sticky area. I can see where some people misuse other people's work. But, you'd have to spend a lot of money to challenge the patent and spend lot of money just to get a patent in the first place. As a group, I know we don't go around making quilt copies to distribute to our friends. But, I don't think nowadays that people are as ethical as I'd wish. We do our best to support the quilting community, but there are some bad guys out there.