Resin Colour Mixing Calculator

Main colour cup = Resin needed × Main colour share ÷ 100, Each other cup = (Resin needed − Main colour cup) ÷ (Colours − 1) — Working in several colours means dividing the resin into cups, and the order matters: combine A and B fully first, then split. Two hundred and twenty grams across three colours is 73.3 g each; give the base colour a 40% share and it becomes 88 g plus 66 g for each of the other two. Leaving the main share at zero returns an even split. Even splits are rare in practice — the background usually takes more than half while an accent needs only a few grams — so setting the base share first and dividing the rest matches how pieces actually get poured. Mix one more cup than you need: once a colour goes muddy there is no undoing it, and a few grams of clear resin held back is what rescues it.

With Resin needed 220g, Colours 3, Main colour share 40%, the answer is Main colour cup 88g.

Enter Resin needed, Colours, Main colour share. The result recalculates as you type, and an empty box counts as zero.

Changing only Resin needed (g) moves the answer to Resin needed (g) 110 → Main colour cup (g) 44 and Resin needed (g) 440 → Main colour cup (g) 176. The table below lays out five steps.

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Combine each cup fully before any pigment goes in. Tint first and you cannot see whether A and B actually married, and an under-mixed cup stays tacky on its own. The time spent decanting comes out of the pot life too: with six cups the last one is already thickening, so for many colours mix in two rounds rather than one. Every transfer leaves 1–2 g on the cup wall, so slightly less reaches the mould than the numbers say. Small cups have narrow bases that rock the scale — set the cup down, zero it, and fill one at a time.