Need a form that tells context?

I have an art website. I want users to be able to contact me about any painting in my portfolio. So, they are on the page with that painting. They have a question about it. Perhaps they want to buy it.

How can I make the form send me the name of the painting, or the painting code number, so I can identify which painting they are interested in?
Without the user toggling cut and paste between the form and the artwork details page?

Can anyone help with that?