How can you tell the difference between a watercolor and a print?

If its a poster, you will have a stamp on the back of where it was made/reproduced. If its an oil painting, it will be on heavier paper, and more than likely, it will be an original. Although, I've never seen one in person, there is a web site that will tell you more. www.rosamond.com.

She worked not only with watercolors, but did several oil and guauche works. They vary in size, but some of her oil paintings are quite large.