A cutting file is a faceting design: every facet's angle and index, in cutting order, for a faceting machine. It tells a faceter how to cut the stone.
In more detail
An .asc design records the refractive index it was drawn for. The same angles behave differently in a stone of another index. Each design names its index gear.
How we measure it
Our cutting files contain a GemCad .asc design, a tier table (.csv) and a printable faceting diagram (.html). Each cut page states how closely the file matches the 3D model.
Related terms
- GemCad .asc: GemCad is Robert Strickland's faceting design program for Windows, and .asc is its text design format. An .asc file gives the gear, the refractive index and every facet's angle and index.
- Tier table: A tier table lists the angle, index positions and cutting order of every tier in a faceting design. Ours comes as a .csv file that opens in any spreadsheet.
- Faceting diagram: A faceting diagram is a printable drawing of a faceting design. A faceter prints it, fits the gear and cuts the stone tier by tier.
- 3D model: A 3D model of a gemstone is a digital solid of its facets for CAD, rendering, printing or games. An exact model has flat facets, sharp edges and a closed, watertight surface at real size.
- Cutting-file accuracy: Cutting-file accuracy states how closely a cutting file's facet angles match the 3D model of the same cut. Each cut page gives the largest angle difference and the mean.