What is Copyrightable?

This is in response to some postings left on my blog by anonymous

Fine fine fine, there's nothing new under the sun so I guess this means I'm free to copy others work now as well. As most of it is what I would definately consider public domain, yet others will defend it to the death that it's theirs. Since I'm not finished with the piece, as I'm sure this is considered public domain as well, can one really say that the quilting stitch is really public or not? I've never seen the pattern in a book, I've only been using it in my designs for a long time now.

It's just a major peeve of mine when the Me Too Me Too band that sees something and wow all of a sudden now they have to put it in their work, not matter how much it looks like crap!!! It's like no one has an original thought in their head, they see someone elses work and can't even be bothered with changing it and making it their own. Ahhhhhh I'm starting to sound like a bitchy artist again, I knew she was still alive and well.

I think I need more chocolate!