![Idea :idea:](./images/smilies/icon_idea.gif)
The traditional way to do this is to cover the plan with a clear polythene sheet or use a candle to wax the surface of the plan, both have drawbacks as adhesives do stick to the surface of the polythene and plan. Recently I came across an idea that Steve Duffy found worked a treat, Cellophane, a material that first appeared arround the second world war, it proof against adhesives sticking to it and it's cheap.
It comes in large rolls (12 metres long by 800 mm wide), big enough for most large model projects, whats more is under a tenner per roll; where do you get this wonder material, most JTF outlets sell it in their florist's department as this is what they wrap flowers in.