Why, I don't know ( perhaps someone here knows ) but all the paper models of tanks I have found all seem to be 1:25, when most commercial plastic kits go for 1:35. I have a load of WW2 armour in plastic kits, but have found some really interesting papermodels of unusual stuff like T35's and T28's which are virtually impossible to get hold of in plastic. Obviousely, I would want to convert these to the same scale as the plastic kits, but would guess that there would be issues with some of the fine detail. How easy is it to scale things like this down? If the models are BMP of JGP format, it;s easy ... but how do I do the same with PDF files? Should I just scale it on the printer, and have a go ... or are there things I should worry about in terms of actual construction and the size of the bits I will have to work with?