Sunprints are pre-treated cyanotype paper that are also child-friendly. The simple instructions call for them being exposed to sunlight and washed under water to develop the image. I have enough photogram experience under my belt, and have made cyanotypes (coating the chemistry myself) only once before. So I decided to use transparency sheets to make digital negatives. My source images included born-digital material and also those from scanned film. At first, I downloaded cyanotype Photoshop curves to adjust my images, but those results were lacking in contrast. (If I had the right personality and ample time, I could burn through packs of Sunprints, testing and customizing my own curve preset.) Based on this first batch, "negatives" with obvious highlights and shadows yield the best results. For the next batch, I won't pick images that have neutral density; areas that consisted of much gray yielded a murky blue picture.
Overall, Sunprints are a cheap way to try out an alternative photographic process, and if making contact prints for object silhouettes, the result still retains some magic.