Mod Podge is an acid-free brand of glue produced by Plaid. Mod Podge is useful for collage and decoupage as it can be used both to glue something down and as a protective layer over it (instead of a varnish). It is available in a gloss, satin, or matte finish.
The company website describes it as a "the original all-in-one glue, sealer and finish"1. The name was derived by its creator, Jan Wetstone, from the terms "modern decoupage"2.Plaid website www.plaidonline.com/apmp.asp, accessed 14 May 2011.