Well, I don't believe 5-meo-AMT blotter is a myth. However I do think people sometimes blame 5-meo-AMT for bad acid trips too quickly.
But we know DOB can fit on a blotter, which is a 2-3 mg dose. That is about a half 5-meo-AMT dose. And I could easily imagine 2-3mg of crystals fitting in the many fibers of a 1/4" bit of blotter. If you take that much material and squish it, it will look like barely anything.
Blotter paper is very absorbant, that's why they use it. Blotter doses of LSD were originally much higher than they are today, and even then they weren't bumping up against the limitations of absorbancy.
You're a shoomery guy right? I think there's some posts over there of people saying they've easily absorbed 5-10mg of material into single blotters...
5-meo-AMT blotter is no myth. Some people are greedy bastards and it's simply too easy and profitable for some people to ignore. If you are selling to a bunch of newbies they will think the 5-meo-AMT blotter is real, and might even have a good trip on it. The advantage over selling blanks in some situations is obvious.