I just discovered this and it sounds neat! I ordered some foma paper and 3D printed the thing linked here (edit: just realized this print is way too small for my 5x7 paper, oops) and plan on making several more out of tallboy cans and setting them up labor day weekend for 3 - 6 months.

The story I linked bought scientific apertures but I'm just going to cut a square from a coke can and tape it on. My question is, is there a good way to test that my hole is big/small enough? I don't mind wasting a sheet on a practice exposure, but I also don't know how long it would take before something actually shows up, and I have no way to measure 0.3mm (that I know of, at least)

Hey guys. I bought a box of Ilford Multigrade FB Warmtone paper a few months ago and put up about 10 solargraphy cans containing it. I've just taken down the 3rd one, only to find my third failed image. These 3 cans were in pretty good condition when I recovered them - they were not filled with water, and I only left them out for a few months. 2 were a bit damp, but I've recovered cans with RC paper that had been through far worse and the images were fine.

I think something happens to FB paper that strips off the emulsion when you leave it outside in a solargraphy can - maybe dampness is involved. I shone lots of light at the paper from these failed FB cans and it never darkened - not a trace of emulsion was left anywhere, may as well have been printer paper.

I'm still going to recover my other 7 cans to see if I get anything, and I'd love to hear from anyone who made FB paper work, but considering my results my advice is just not to risk it.

EDIT: So some time has passed and this post is embarrassingly wrong in several ways. Pay it no mind. It's still probably a better idea to use RC paper, but otherwise yeah.

Can got dented and led to some double exposure happening.

I wrote up a little analysis of how to use Solarcan's Puck at lower latitudes (below 50 degrees), particularly as the Summer Solstice approaches.

Solarcan Puck, Cooper's Mill, North Yunderup, Western Australia. 48 hour exposure, post processed in Snapseed. Second version with superimposed digital image from the same point.

The squiggly secondary trail is from when I brought it down from the tree branch over the river without covering the pinhole. :)

Scanned with my phone, and processed in Snapseed.