How to Choose a Butterfly Pinning Board

Most people buy their first pinning board by picking the cheapest one that looks about right. Then they rehydrate a hawkmoth, try to seat it in the groove, and find out the body does not fit. Or the wings hang off the edge of the panel. Or everything looks perfect on day one, and three months later the wings have dropped.

Quick note on names first, because this is where people get lost searching. Pinning board, setting board, spreading board, mounting board. Same tool. Setting board is the British habit, spreading board is more common in the US, and I have always called them pinning boards. Call it whatever you like, it is the same piece of wood and foam and this article is about all of them.

A pinning board is a simple piece of equipment. But four numbers decide whether it works for the specimen in front of you.

Fifteen years of getting this wrong before getting it right

I have been making pinning boards for about fifteen years, and I have been through most of the bad versions along the way. Grooves that were a millimeter off. Surfaces that went hard after a season. Boards that warped.

Everything I sell now is what I actually use. My own collection is set on these boards, and so is every single spread butterfly and moth that goes out of the shop. My friends in the hobby have all switched over to them, which is honestly the review I care about more than any other.

So the sizes below are not marketing categories. They are the sizes that turned out to matter.

1Groove width: the part people get wrong

The groove has to fit the body. Not loosely, not tightly.

Too narrow and the body will not seat. You force it, and you either crush the abdomen or end up with the two wings sitting at different heights. Too wide and the body swings in the gap, the wings lose support right where they leave the thorax, and the specimen dries crooked.

Hawkmoths are the classic trap. The moth looks big, so people buy the widest board, and then that thick body will not go into a 10 mm groove. That is why the Large Pinning Board has a separate HAWKMOTH size: a wide groove with medium panels, which is the opposite of what most people reach for.

If you work with mixed material and do not want to own six boards, the Adjustable Pinning Board solves it in one piece. One panel slides sideways and locks, so the groove goes from almost closed to wide open.

2Panel width: measure the wing, not the wingspan

The panel has to be at least as wide as one wing, from the body out to the tip. That is roughly half the wingspan, plus some margin so you have room to place setting pins outside the wing.

So a 13 cm butterfly needs about 6.5 cm of wing sitting on a panel, and you want a 6 cm panel as an absolute minimum. This is why the sizes in my range look the way they do:

If the wing tip runs off the end of the panel, the tip dries unsupported and curls. There is no fixing that later.

3The angle: why boards are not flat

Wings do not stay exactly where you put them. As a specimen dries, and later as it reacts to changes in humidity in the room, the wings settle slightly downward. Set them dead level and they will finish below level.

That is what the angle is for. The panels rise away from the groove, so you set the wings a little above horizontal and they come to rest flat. Eight degrees is the working standard, and it is what my Standard and Large boards use. The one exception is the widest panel, the 10 cm LARGE size, which sits at 10 degrees. These settings come from fifteen years of pinning on my own boards, and for a collection you rarely need anything else.

There is a second reason and this one is just my own opinion, so take it as taste rather than technique. A wing sitting at a slight angle simply shows itself better than a wing lying dead flat. You read the shape of it properly, and the pattern does not flatten out the way it does on a completely level specimen. After fifteen years of looking at both, the angled ones are the ones I keep coming back to.

When you want a flat board instead

There is one job where the angle works against you, and that is framing.

Set a butterfly at 8 or 10 degrees and the wing tips finish slightly higher than the body. In a deep shadow box that is fine. In a shallow frame, those raised tips are the first thing to touch the glass or the plexiglass, and a wing pressed against glazing is a wing that gets damaged.

If you are framing your specimens, spread them on a Flat Pinning Board. Everything finishes in one plane and sits clear of the glass.

The one I had to build myself

4Length: it decides how fast you can work

Length has nothing to do with how big a specimen you can mount. It decides how many you can mount at once.

Classic boards run 30 to 40 cm and mine are 29.5 and 39.5 to 40 cm, which is the same range for the same reason. It fits a comfortable session's worth of specimens.

This matters more than people expect, because of drying time. A board is occupied for weeks, not hours. If you rear or collect in any volume, the number of boards you own is what limits your output, not your skill. It is also why the small boards sell as a set of three sizes rather than one at a time.

5Surface: what you actually pin into

Both hold a pin properly, which sounds obvious until you have used a board that does not. If the surface has gone soft and loose, your setting pins drift while the specimen dries and you find out three weeks later.

6The line grid: the upgrade people notice most

The standard wing position is the inner margin of the forewing at 90 degrees to the body. Simple to say, surprisingly hard to see by eye.

So my boards come with line grid stickers: fine parallel lines running across the panels, square to the central groove. You line the forewing margin up with a printed line and you know you hit 90 degrees. You count lines on the left and the right and you know both sides match.

Without a reference you are eyeballing symmetry, and the human eye is genuinely bad at it. Every specimen you set slightly crooked stays slightly crooked forever. Of everything I have changed about these boards over fifteen years, this is the one people write to me about.

Grids come on the Standard with Grid Sticker and Large with Grid Sticker boards, and are included with both adjustable boards.

What about micro-moths?

Fair question, and the honest answer is that none of my boards are right for them.

Micros are a different discipline. You pin them with minuten, which are several times thinner than a normal entomology pin. Instead of foil strips you hold the wings with 3 x 3 mm paper squares, pinned with a size 00 pin cut down to 10 mm, and the paper is only supposed to touch the wing, never press it down. All of it happens under a binocular microscope at 16x, and determination often needs 30x. The boards themselves are tiny and cut from soft balsa.

Which board for which job

One last thing: leave it on the board longer than you think

The best board in the world will not save an under-dried specimen.

A freshly killed butterfly needs roughly three to four weeks on the board, depending on how heavy the body is. A rehydrated one can come off sooner, but even then do not touch it before ten days.

The test is the abdomen. If it is hard and does not move, the specimen is dry. If there is any give, leave it.

Take a specimen off early and the wing joints have not finished setting. They keep reacting to the humidity in the room, and over the following months the wings slowly rise or drop. It looks like the board was wrong. It was not.

Write the date on the board when you fill it. Sounds trivial, saves you guessing three weeks later.

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