Never tried tap water it might work, a lot less than you pay for film guard that's for sure. If you read Roberts previous download from the Kodak website, it hints that the edge of the film and perforations need to be lubricated for reduced wear, how on earth can you apply this liquid with such accuracy without blobbing it on the film frame with a cloth between your fingers, and Kodak go on to say a machine is required to do this correctly, my point and the point I have been trying to make, I know you think your the leader of the Pack Andrew, with pages and a pages of technical twaddle that only you understand, but your not the school teacher here and I'm the school boy learning from the back of the class, not so not in a million years....... I repeat again not ONE of the films I own or have owned ever needed this film guard to help it through the projector or make it quieter in doing so, some film I own may have the stuff on, but without close examination I could not tell you which it was or when it was applied. Apologies to Martin Dew for hijacking this subject, I will say no more, so Andrew as always can have the last word ..................