copyright question

Hi, I'm not exactly sure where this topic belongs so bear with me. I am wonder what are the copyright laws on artwork from painters in the past. I'm doing some pictures for tshirts and I want to use art work from the different periods from history. Like works for cezanne, picasso, monet, etc. How does copyright work for artists like these? I'm not planning on just sticking the painting on the tshirt, but probably modifying it bit to fit what I want. Any ideas regarding this? thanks!

Copyright is one of those very grey areas as there are different laws for each nation, and extensions, amendments, exceptions, etc. that it gets pretty heady, very quickly. As a rule, the use of the underlying art, of a "classic" will be public-domain, but where it can get dodgy, is that the actual photograph of the art, under certain circumstances, may be copyrighted.

Here's Wiki's take...

http://en.wikipedia.org/wiki/Public_domain

yea guess I'll have to do a bit of research into this
thanks a lot!