“White matte” is a colour on a screen. A printer needs a sheet. The sheet has a fibre, a weight, a finish, and a caliper, and those four facts decide what the finish can do.
Weight is not thickness. Two sheets can share a basis weight and differ in caliper, and caliper is what you feel and what a foil stamp has to cross. Finish changes the same weight again: a smooth sheet takes fine foil, a toothy cotton sheet takes a deeper bite and loses hairline type.
Write the specification on the drawing before you draw the gold. If the plate only says the finish, you have decorated an unknown object.
How to check it
- Read the label. It should name fibre, weight, finish, and caliper, not a mood.
- Match the finish to the sheet. Fine foil on rough cotton, or a deep emboss on a thin hard sheet, will fail in production.
- Do not treat opacity, brightness, and thickness as one dial. They move separately.
Usage
.sheet {
/* Specification, not a swatch name. */
--fibre: cotton;
--weight: 300gsm;
--finish: eggshell;
--caliper: 0.45mm;
}