HO & O - High Quality Scale Modeling Architecture and Railroading

Milk comes in these square, plastic half gallon milk jugs with mostly flat sides. My wife is kind enough to wash them out for me. I then cut out the four flat sides to use as window material.
The oval shaped flat pieces from each side cut easily with a hobby knife and metal straight edge. The milk jug plastic is very slippery so be careful it doesn't move under the straight edge while cutting. Pick up some HALF Gallon jugs next time you're in a super market. The gallon jugs are of course larger, and the sides are rounded so they're not good for windows.