So I've been given tentative permission to transform a sauna in my mother's house into a print darkroom. Advantages: it has its own door into a bathroom, it has good ventilation, and it's big enough to accommodate a 6x6 enlarger. It's "intimate" in terms of space, but do-able. There's access to electricity, there's access to water, and the temperature is easy to control. Problems: Big honking window, and big honking glass door. So I'm wondering if I can block out the windows by means of black vinyl adhesive panels as used in signmaking. And I was also wondering if there's a translucent red vinyl that can be used as a 'safelight' window ... any thoughts on this? Maybe by putting big red photographic gel filters on the window and sticking them in place behind the black vinyl?