I picked up the Etched Leaf pattern of the Artscapes film at Home Depot to provide privacy, but light, for a basement door with a big window in it. It's really lovely and was easy to do. Unlike the old contact paper, this is a cling film so it's easy to remove, reposition, etc. I'm not sure I got every last bubble out of it, but the pattern hides that well. I don't know if it will yellow or get brittle in the long term, but it's not too expensive so I'd be willing to replace it if I needed to.

As a do-it-yourself matter, you are wise to be cautious. Film applied on the inside of mult-pane windows has great potential to cause heat build-up. Something has to give and often it is the glass exploding on a cold day. As a matter of hiring a professional window film dealer, I always advise a homeowner to get a written guarantee. If the installing dealer promises you won't have any problems have him put that in writing to include replacing and/or repairing any glass or parts damaged as a result of the film. I have seen such a written guarantee by reputable and knowledgable installers. I did business with a solar film specialist some time ago that had a product he applied to exterior of glass and gave a strong guarantee to his customers. Best results will come from having the outside piece of glass be colored or tinted, either reflecting or absorbing heat and/or intense sun. If you are keeping the storm windows consider having a reflective glass installed in them.

I have applied the Gila frost-look window film. I had to because my dog couldn't tell the patio door was closed. Ouch! Anyway, I decided a few months later that I overdid it and wanted to trim down a bit. It was really stuck on good. I used a razor blade and carefully scraped away the excess. I would definitely not hesitate to buy it again. It looks like they have made some changes since I bought mine. "How do I remove old window film? EZMount adhesive by GILA makes film removal easy and clean. Removal is as easy as peeling the film away from the glass. However, depending on when you purchased your film, it may not contain EZMount adhesive. If your film has been installed for a while or it doesn't remove easily from the glass when pulled, please follow the instructions below We recommend the GILA Window Film Removal solution as one of the best ways to remove old window film and adhesive from glass. This solution is sold at the GILA Window Film display at major home centers nationwide. One bottle removes between an average of 45-60 sq ft of film, depending upon how many years the film has been on the window and its exposure to direct sun. " Here is a link that might be useful: Gila Window Films

Ok thanks everyone. Could someone clarify for me these things: I think I understand about mirrored window film now and its advantages/disadvantages. And I already understood, more or less, frosted window film. I guess it comes down to covering with some semi-sheer cafe curtains/valance and then doing the window film as an added block. So the ultimate question is, of mirrored and frosted window film, which would ultimately block less light? Thanks :) Oh--and just to clarify for those who missed it and suggested coatings, consulting w/ pros, etc.: I rent. I should've stated that.