Epoxy Pigment Calculator

Colourant is dosed by weight, as a percentage of your mixed epoxy. Enter how much resin you are mixing and this works out the dose, and tells you when you are about to add too much.

Pigment Calculator

Mixed epoxy

fl oz

Measured by

Colourant type

Percentage of the epoxy weight. Start low and build up, because you cannot take colour out.

Safe maximum: 5%

How much to add

Colourant to Add

1.402oz

Mixed epoxy weight: 1,987 g
Colourant type: Mica powder
Safe maximum at 5%: 3.505 oz

Recommended for this pour

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Mica Powder

Fine mineral powder for pearlescent and metallic effects. It sits in suspension rather than dissolving, so it needs thorough dispersion, and stays workable up to roughly 5% of the epoxy weight.

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Essential mixing tools

How Much Pigment to Add to Epoxy Resin

Colourant is measured as a percentage of the weight of the mixed epoxy, not its volume, and not the volume of resin alone. That trips people up, because most epoxy is measured by volume in the first place. The conversion runs through the density of the mixed resin, which this calculator handles.

1
Weigh the mixed epoxy, or convert from volume
Mix Part A and Part B first, then take the combined amount as your basis. If you measured by volume, multiply by the mixed density, which for most epoxy sits near 1.05 grams per millilitre. The calculator does this for you, and the epoxy weight to volume calculator shows the conversion on its own.
2
Start at the low end of the range
Mica powder is usually run between half a percent and three percent by weight. A pale wash of colour needs far less than people expect, and you can always add more. You cannot remove colour once it is in the cup.
3
Add the colourant to Part A where possible
Many makers disperse pigment into the resin side before adding hardener, which gives more working time to break up clumps. Mix thoroughly, scraping the sides, then add the hardener and mix again. Undispersed mica leaves streaks and dark specks.
4
Respect the maximum
Every colourant has a ceiling. Beyond it the pigment stops being suspended and starts interfering with the chemistry, giving soft spots, tackiness or a cure that never fully hardens. If you need a more opaque colour, use a pigment made for opacity rather than more of a translucent one.

Mica Powder, Liquid Dye and Pigment Paste

The three common colourants behave very differently, and their safe loadings are not interchangeable. Manufacturers vary widely as well, and some cap every colourant at 3%, so your own data sheet outranks the figures below.

Mica powder, up to about 5%

A fine mineral powder that gives pearlescent and metallic effects. It sits in suspension rather than dissolving, so it needs proper dispersion and will settle in a very slow cure. Typical use is one to three percent, with five percent as a practical ceiling.

Liquid dye, up to about 3%

Transparent colour that dissolves into the resin, ideal for tinted river tables where you still want to see through the pour. It is potent, so doses are small. Overloading is easy and is a common cause of a soft cure, so one percent is a sensible starting point.

Pigment paste, up to about 6%

A concentrated opaque colourant already dispersed in a carrier. It tolerates heavier loading than the other two and is the right choice for solid, non transparent colour. Check the manufacturer figure, since carriers vary between brands.

Epoxy Pigment Questions

How much mica powder per gallon of epoxy?

A US gallon of mixed epoxy weighs roughly 3975 grams at a typical density. At a two percent loading that is about 80 grams, or just under 3 ounces of mica powder. Enter your own amount above for the exact figure, or size the batch first with the epoxy volume calculator.

Is pigment measured by weight or by volume?

By weight, as a percentage of the mixed epoxy. Powders in particular vary enormously in bulk density, so a spoon measure is not reliable. A cheap kitchen scale that reads to a tenth of a gram is the single best upgrade for coloured pours.

What happens if I add too much pigment?

The resin may cure soft, stay tacky, or fail to harden in places. Colourant does not take part in the cure reaction, so past a certain point it simply gets in the way of it. There is no fix once it has cured, so the pour has to be cut out.

Can I mix pigment into Part A before adding hardener?

Yes, and many people prefer it. Dispersing into the resin gives you longer to break up clumps before the pot life clock starts. Just remember the dose is calculated on the combined weight of both parts, not on Part A alone.

Do I need to change the mix ratio when adding pigment?

No. The resin to hardener ratio is fixed by the chemistry and colourant does not change it. Mix the two parts at their correct ratio, then add pigment as a percentage on top.