How to make a room dark

 Notes for my future self. Use layers of materials on the windows. Step one was foil. I had bought some extra thick foil a few weeks before but ended up using it during cooking and was left with the inferior stuff. Not fit for purpose really. A good roll of low-tack fabric-style gaffa tape, not only saves the window surround paint work but is a pleasure to use.

Next I cut polystyrene to size, obviously I'm not a fan of the stuff, but we had a package delivered that had  lots of it in, perfect for the moment.

Then because I was projecting on that wall, some very thick white paper. 

Then on the other side of the window, outside,  a huge tarpaulin clipped to the window frame. We started the shows on the shortest day of the year for maximum darkness. The first show was at 1pm. This didn't feel so dark, but by 2.30pm it was pitch! Audience comments included 'it was dark, then it seemed to get darker'. 

We made sure people started off in a very bright room, as it was nearly Christmas, we used tonnes of fairy lights. They walk into the room, are sat down, shown the safety light and plunged into darkness.

Folks were brought back into the light gently by my lovely companion, the slide projector. They found themselves in a darkroom. Which gave us all the idea to do a KlangHaus in a photographic darkroom in the future.... ooo... pictures emerging from the dark, the smell of chemicals, sounds whizzing round, red lights, shadows.

Here is one reaction that made me glow...