Size classes, and why they exist
Updated
A century-old convention that decides boxes, drawers, prices and what a collection can be.
A trading convention
Collectors and dealers describe specimens by size class rather than by dimensions, and the classes are understood the same way across the hobby.
It works because it is a bounding convention: a specimen belongs to a class if it fits within that cube in any orientation.
The classes
Micromount. Viewed under magnification, mounted in a small box.
Thumbnail. Fitting a one-inch cube.
Miniature. Roughly to two inches.
Small cabinet, then cabinet, the display sizes.
Terminology varies at the edges and the small end is the most consistent.
Why they matter
Boxes, cushions, flats and drawers are all made to them, so a class decision is a storage decision.
Prices are quoted within them, so a class is how you compare two specimens at all.
And the class determines what a collection can be: a thumbnail collection of a thousand specimens fits in a cabinet, and a thousand cabinet specimens fill a room.
Choosing a class to collect
This is the most consequential early decision in the hobby and people often make it by accident.
Micromounts: the widest species coverage, the lowest cost per specimen, requires a microscope, nobody else can see it.
Thumbnails: high quality per pound, compact, affordable, and the best access to rare localities.
Miniatures: the balance collectors often end at, visible without aid and still storable.
Cabinet: the most impressive and the most expensive by a wide margin, and it needs a room.
Choosing one and holding it is what produces a coherent collection. Collecting across all four produces a storage problem and a shallower collection at every size.