Spreading boards come in a variety of materials, sizes and styles.

Typical woods are balsa and lime.  Both will take pinning and re-pinning numerous times without showing wear.  For those of you buying for younger entomologists, please note that balsa is very easy to "ding" and damage to the edges of the boards can happen quite easily.

Plastazote is easier on the fingers - pins slide in like a hot knife in butter!  A good board for the younger crowd.

Angled boards are the most commonly used; with the wings in an angled position, the insect has a more "lifelike" appearance.  However, this is (as always) a matter of preference.  For some moths and butterflies, the flatter appearance can "show off" the wing pattern more clearly.

A final note:  for those of you who are less familiar with the process, the size of the body and the wings of the insect being spread and dried will dictate the width of the groove and the board.  The body rests in the groove, and the wings are spread on the two sides of the board.  Clearly a Polyphemus moth will need greater width in both areas than a Cabbage white butterfly.  The length of the boards allows for a number of specimens to be spread at the same time.