AGFA X-RAY CP-BU M

My first ever box of X-ray film was a slightly damaged box of Agfa CP-BU M from eBay that I got on June 5, 2024 for $18. CP-BU M is a double-sided blue-sensitive film, on a ~7 mil blue base. Like any X-ray, it has a decent amount of silver but large grain and a soft emulsion that scratches very easily. It has four rounded corners, and comes in 8x10, 11x14, and 14x17. It's basically the cheapest X-ray film on the market from a lot of vendors, with a 100-pack of 11x14 selling for only $80 in some places, but it is much worse for pictorial use than the Fuji HR-U green films.

The Agfa stock is a great tool for experimentation, though, due to its very low price. It also seems to be a cheap source of a lot of 7 mil PET -- for $18, I got effectively 100 8x10 sheets of good PET base. To harvest it, I use a somewhat primitive process (the accepted method is a soak in 1:1 Clorox):

1. Expose the sheet to light and soak it in hot water for at least ten minutes. My tap runs between 135-140°F in all seasons.
2. Develop the sheet out, usually in dilute HC-110. This makes the emulsion as visible as possible.
3. Wash the sheet with a few more rinses of hot water in its tray.
4. Under the hot water, brush the sheet with the IKEA brush. It was two dollars, but you still have to rinse it. This will soften the emulsion and let it mush in a way that lets it wash off in the water bath.
5. Finish brushing the sheet, then soak for five more minutes in hot water.
6. Sit the sheet on some newspaper and use a paper towel to remove any stubborn emulsion, then rinse with hot water two more times.
7. Dissolve one detergent packet in a hot water bath (use ventilation) and agitate the sheet in it for two minutes.
8. Rinse in hot water two more times and hang to dry.

There are a few applications for this PET, but my favorite is carbon tissues. I've been a little obsessive about carbon printing since December of last year, and cheap tissues are great. Not only is the Agfa X-ray plastic cheap, it comes with a gelatin size if you fix it or can be albumen sized easily. The tissues made with it are clean and dimensionally stable, and exhibit no curl even in bad conditions. They're also cheaper than the clear Dura-Lar, at least in small sheet sizes. More importantly, I already have them. Soon, I really want to experiment with panchromatizing them with erythrosine B and pincyanol as Denise Ross described, though that's a long ways down the road. The two problems with the X-rays as a gelatin support or base are 1. that they are blue, and 2. that they are pretty resistant to registration pins because they have a decent thickness. With a mild warm water + detergent pod soak, it's a fairly good carbon tissue. It's worse than the Fuji stuff for the new ferric carbon, though, since the base is significantly thicker. I'd probably rather use a thinner dedicated clear film for that anyway.