This Hammer paper model is from the film "Thor", designed by George S. The picture is from Tektonten's blog. There are other papercrafts about "Thor" at this site: "Mjolnir War Hammer Free Paper Craft" and "Marvel Comics – Thor Free Papercraft". This is a 1:1 life size paper model.
About this Mjolnir hammer papercraft:
Size per page: 11" x 17"
Hammer dimensions: 8.5" (hammer head width) x 5" (hammer head height) x 16" (total hammer length)
You can download this paper model from here: Thor - Mjolnir Life Size Papercraft Free Download