Marble Gauge Sizing Tool for Collectors, 3/8" to 1-1/8"

A brand new sizing gauge made for marble collectors and dealers. Drop a marble through the holes; the smallest hole it passes through is its size. Sort a lot in minutes without touching a single vintage marble to metal.

Precision cut from 1/8 inch (0.118) clear acrylic with a frosted back. The design is engraved in reverse on the back and reads correctly through the clear front, so the markings never wear off and stay legible on any surface. 5.5 by 5.5 inches with rounded corners, sized to sit on a desk or slip into a show bag.

Fourteen holes cover the sizes collectors actually deal in: 3/8, 7/16, 1/2, 9/16, 5/8, 21/32, 11/16, 3/4, 13/16, 7/8, 15/16, 1, 1-1/16, and 1-1/8 inch, each labeled in both fraction and decimal. The 21/32 hole is there for the many vintage marbles that fall between 5/8 and 11/16. Each hole is cut slightly over its nominal size on purpose, so a marble that runs slightly large for its size still drops through and reads correctly, the same way the original factory sieves worked. A 5 inch ruler runs along the bottom edge, and a quick key for peewee, standard, and shooter is engraved above it.

Acrylic will not scratch, chip, or mark glass, which makes this safer than the metal calipers most of us reach for, and a lot faster than the drafting circle template collectors have been borrowing for this job for decades. It is not a substitute for digital calipers when you need a reading to the thousandth, but for sorting, grading, and writing accurate listings it is the tool you will reach for first.