Insect pins are used by entomologists for mounting collected insects. [2] They can also be used in dressmaking for very fine silk or antique fabrics. [3]
As standard, they are 38 millimetres (1.5 in) long and come in sizes from 000 (the smallest diameter), through 00, 0, and 1, to 8 (the largest diameter). [2] [4] [5] The most generally useful size in entomology is size 2, which is 0.46 millimetres (0.018 in) in diameter, with sizes 1 and 3 being the next most useful. [2] [4]
They were once commonly made from brass or silver, but these would corrode from contact with insect bodies and are no longer commonly used. [2] Instead they are nickel-plated brass, yielding "white" or "black" enameling, or even made from stainless steel. [4] Similarly, the smallest sizes from 000 to 1 used to be impractical for mounting until plastic and polyethylene became commonly used for pinning bases. [2]
There are also micro-pins, which are 10–15 millimetres (0.39–0.59 in) long. [4] minutens are headless micropins that are generally only made of stainless steel, used for double-mounting, where the insect is mounted on the minuten, which is pinned to a small block of soft material, which is in turn mounted on a standard, larger, insect pin. [6] [7]