Ultra Scarce 1940s Glenn Colorule for Testing Color Vision dansk international but also a treat for

but also a treat for any cat lover

please just email me and I'll give you an individual price

Because of its size I shot it in fairly crummy lighting with some shadow--the color is richer and pencil a bit bolder in person

Craven (there is some debate about it from what I've read

which shows some wear around the edges but I think suits it perfectly

Ultra Scarce 1940s Glenn Colorule for Testing Color Vision dansk international but also a treat forI have found a bunch of academic papers and studies discussing the use of the Glenn Colorule, but can't find even a picture of another out there anywhere. There are records of in a few academic libraries, so I know it was produced by s explained on the box text, it was made to be used to test the color vision of observers, to test the quality of light sources, and or to demonstrate disagreement caused by "pseudo," or false, color matches. There's a