These were made in the back garden with sunography kits. You put objects on the paper/fabric, cover with glass or plastic to hold everything down, then leave them to expose. It takes 10-15 minutes in bright sun, the weather turned cloudy when we did ours and the orange one ended up having close to an hour. Once exposed, you rinse the prints under running water for at least a couple of minutes and dry them on kitchen roll/paper towel, swapping for a dry towel after 15 minutes. There is no fixer required.
We found that although you can expose on both sides, the image from one side will show through slightly to the other side.
Fox Talbot and Anna Atkinson were early pioneers of photograms. They tended to be of horticultural specimens rather than underwear, however Fox Talbot made several using lace.
I am exploring this because I want to make a calotype of the Fox Talbot window by deconstructing a polaroid image and using the emulsion as a negative on Sunography paper.