It is cheaper and larger than wax paper for covering your plans clean and free from glue when building.
They make great windows on planes with flat window panes like most old timer style planes.

I have also done some trials scanning older, cracked decals that would disintegrate if they ever got wet and printing on the adhesive side of the Doculam with mixed results.
I haven't been completely succsessful but some of the tests have some really good potential it seems. judge for yourself.

Robert