The Paper Toy Construction Set is a collection of jpg images of struts and girders in a variety of sizes, shapes and angles. The idea is that you print out these pieces and then use them to build your own models — much like an erector set.
Paper Models
Paper Testudo Model
For Warhammer Ancient Battles, here is a paper model of a Roman testudo in 25mm/28mm scale.
Paper Model of An Elf Tower
I’m not at all sure what scale this free paper model of an elf tower is in. Its either a big 15mm or a small 25mm scale. In either case, it would be a nice addition to the table for a fantasy game.
Half Timbered Town Houses
Here’s a site with four very nice paper models of 25mm / 28mm half-timbered houses that would be appropriate for a fantasy or medieval town setting. There are “shoddy shops” a “posh place,” a plain half timbered house and a building that is more fantasy oriented. All are in pdf format.
Back to The Future Steam Train Paper Model
Paper Insider has a free paper model of the time traveling steam train from Back To The Future III. I really can’t tell what the scale is, but from the side panels, it may be ok for 25mm.