1. How do I preserve my blueprint images?
That’s a good question. There is no sure fire way to do it, given the nature of commercial blueprint paper, but a few things are known to help:

• UV protection (UV filtering glass, UV filtering plastic film, etc)
• Protection from air
• Acid-free mounting
• Avoiding contact with skin oils

2. How long does a print take?
It depends entirely on the amount of light getting to the paper, and the speed of the paper. A contact print in the sun takes only a few seconds while an enlargement using an overhead projector can take 45 minutes or more, and a slow lens in a camera may require 6 hours. In contrast, I have a fast lens that can make an image in 10 minutes with full sun. The paper is cheap, so experiment!

3. How is commercial blueprint paper different from sunprint paper?
To the best of my knowledge, sunprint paper is more of an art supply that is intended for home use, usually only requiring tap water to ‘fix’ the image. I’m told that it’s more costly and far less sensitive.

4. How is commercial blueprint paper different from cyanotype photo paper?
Cyanotype paper is a negative process photo paper, and a variety of formulas exist. Sensitivity is similar to commercial paper at around 7 speed, and fixing varies with the formula. The cyanotype process is one of the oldest known photographic processes.