Avid Reader: This was a cover for "Ring of Fire IV," part of the 1632 Series of alternate history books edited by Eric Flint. The story Tom illustrated had a 17th century young boy reading 20th century science fiction magazine. Each of the covers shown in the painting are covers he actually did for those magazines.
The print is 8 1/2 x 11 inches, the image is approximately 7 x 9 inches. It is shipped flat in a protective sleeve.