Sheen is measured in gloss units at 60° — a number your spec sheet should carry, because 'matte' means five different things to five suppliers.
The scale in practice
Super-matte sits near 5 GU: velvet, print-hiding, premium-modern. Matte 10–15 GU is the versatile default. Satin 25–35 GU wipes cleanest and suits profiles. Semi-gloss 50–60 is traditional trim territory. High gloss 85+ is polished mirror for feature runs.
Sheen changes colour
Identical pigment reads darker and richer as sheen drops, lighter and sharper as it rises. Whites at high gloss can look clinical; blacks at super-matte look expensive. Approve colour in the final sheen, always.
Writing it into the spec
State RAL plus GU target plus sheen name — 'RAL 7009, matte ~12 GU' ends supplier ambiguity. Our samples ship labelled exactly this way so approvals hold through production.