Take a rectangular piece of polyethylene foam used as bottom inlay for insect boxes (or use something similar), about 5 by 5 cm. Take an apple corer and rotate very slowly with mild pressure into the foam to get the nice round hole in it. It exactly fits a finger! I usually use it on my forefinger or my thumb; sometimes I use two at the same time! And you can pin multiple specimens on one at the time and compare them. A very convenient life-hack for an entomologist.
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