Getting the right look starts with knowing exactly how much pigment to add to epoxy without ruining the cure. It's one of those things that feels like a guessing game when you first start. You're staring at a clear cup of resin, holding a jar of vibrant blue powder or a bottle of liquid dye, and you're wondering if a tiny scoop is enough or if you need to go heavy-handed to get that deep, rich color you see on Instagram.
The honest truth is that there isn't one single "magic number" because it depends on the project, but there is a very strict safety limit you need to stay under. If you add too much, your resin won't harden properly, and you'll end up with a sticky, rubbery mess that never fully cures. Let's break down the rules so you can get the color you want without wasting your materials.
The Golden Rule: The 5% Limit
If you remember nothing else from this, remember the 5% rule. Generally speaking, you should never add more than 5% of pigment by weight to your total mixed epoxy (resin plus hardener). Some pros even suggest staying under 3% just to be safe.
Why is this so important? Epoxy is a chemical reaction. When you mix the two parts together, they link up on a molecular level to create a hard plastic. When you dump in a ton of pigment—whether it's powder, paste, or liquid—you're basically shoving "stuff" in between those molecules. If there's too much "stuff" in the way, the resin molecules can't find each other to bond.
The result? Your table or coaster stays flexible, or worse, it stays tacky to the touch forever. To stay safe, if you're mixing 100 grams of epoxy, keep your pigment under 5 grams.
Different Pigments Require Different Amounts
Not all colorants are created equal. Depending on what you're using to tint your resin, the amount you'll need to achieve a specific look will vary wildly.
Mica Powders
Mica powders are probably the most popular choice for beginners. They're easy to handle and give you those beautiful pearlescent swirls. Because mica is a solid mineral that just floats in the resin, it's pretty forgiving. Usually, a tiny spoonful (like the ones that come in the jars) is enough for a small batch.
If you want a translucent look where light still shines through, you only need a dusting. If you want a solid, opaque look, you'll add more, but even then, you'll rarely hit that 5% danger zone because mica is so light.
Liquid Dyes and Tints
Liquid dyes are super concentrated. They're meant for that "stained glass" look. For these, you should start with one single drop. Seriously. Mix it in, see how it looks, and then add another if you need to. Because liquid dyes are often made with chemicals that can mess with the resin's chemistry, you have to be extra careful not to overdo it.
Opaque Pigment Pastes
Pastes are the heavy hitters. If you want a solid white or a deep, flat black that you can't see through at all, pastes are the way to go. They're extremely thick and highly saturated. You usually only need a pea-sized amount for a significant amount of resin. Since they're so thick, they can really affect the cure if you get carried away, so use them sparingly.
How the Depth of Your Pour Changes Everything
This is a detail a lot of people miss. The "how much" question actually changes based on how thick your project is.
If you're pouring a thin 1/8-inch coating on a countertop, you need a high concentration of pigment because there isn't much "depth" for the color to build up. If the pigment is too thin, the countertop underneath will peek through.
On the flip side, if you're doing a deep pour for a river table that's 2 inches thick, you actually need less pigment per ounce. If you make the resin as dark as you would for a thin coat, a 2-inch deep pour will look like solid, muddy plastic. You won't be able to see any of the depth or the wood grain on the sides. For deep pours, "less is more" is the mantra. You want the light to be able to travel through the resin to show off the internal character.
The "Add as You Go" Method
Since it's impossible to take pigment out once it's in there, the best way to figure out how much pigment to add to epoxy is to do it in stages.
- Mix your resin and hardener first. Always make sure your epoxy is fully mixed before you start coloring. If you add pigment to just Part A, it can be hard to tell if you've mixed Part B in thoroughly later.
- Add a tiny bit. Use a toothpick or a small stir stick to add a small amount of your colorant.
- Stir and check. Mix it thoroughly. Sometimes a pigment looks light when it's in a clump but spreads out to be much darker.
- The "Stick Test." Dip your stir stick into the resin and lift it out. Look at the resin dripping off the stick. If it looks the color you want in that thin stream, it's going to be very dark in the cup. If it looks transparent on the stick, it'll be semi-transparent in your project.
Dealing with "Bendy" Resin
If you find that your project is still a bit flexible after the full curing time, there's a good chance you added too much pigment. This happens a lot with alcohol inks, which are popular for "petri dish" art. Alcohol inks contain—you guessed it—alcohol. If you put too many drops in, that alcohol prevents the epoxy from hardening.
If your piece is just a little bit bendy, sometimes you can save it by giving it a few more days in a warm room. But if it's been a week and it's still soft, you've likely exceeded that 5% threshold, and unfortunately, there's no way to fix that other than starting over or using it as a base for a second, properly mixed layer.
Mixing Colors and Getting Creative
Don't feel like you're stuck with just one type of pigment. A lot of makers find that the best results come from mixing. Maybe you use a little bit of blue mica powder for the shimmer, but you add one drop of transparent blue liquid dye to give the "water" more color depth.
When you're mixing different types, the 5% rule still applies to the total weight of all pigments combined. Don't do 5% mica and 5% paste, or you're asking for a sticky disaster. Keep the total "additives" to a minimum.
Final Thoughts for Your Next Project
At the end of the day, figuring out how much pigment to add to epoxy is a bit of an art form that comes with practice. If you're working on a high-stakes project like an expensive piece of furniture, do a test pour first. Use a small plastic cup and a few ounces of resin to see how the color reacts and cures. It's a lot cheaper to waste two ounces of resin on a test than to ruin a massive project because you wanted it to be "just a little bit darker."
Keep it simple, start small, and always keep an eye on that 5% limit. As long as you don't overwhelm the chemistry of the resin, you've got a lot of room to play with and create something awesome. Happy pouring!