Freezer paper is used by meat markets, locker plants, and supermarkets to wrap fresh meat in so it can be stored in a freezer. There are two very distinct sides to freezer paper. The outside has a white dull-coated finish, while the inside is coated with a thin layer of wax. This is to help prevent freezer burn to the meat, and keep any fluid or moisture from saturating the paper, until the meat is frozen. It can be purchased by anyone at most supermarkets and discount centers in various roll lengths and widths.
Price is just a bit more than aluminum foil.
Before I began, I made copies of the plans I was using so as not to destroy the originals. And yes, making copies can impede your line width and possibly the scale somewhat. If there is a blueprint copier available, use that. The way to over come that, is to draw your dimensioned part directly onto the dull side of the freezer paper. It is very easy to mark on and quite sturdy.