Mica Powder 101: The Art of Adding Sparkle
Updated Jun 2026TL;DR: Mica powder is a mineral pigment, not glitter, and not opaque pigment paste. It gives resin a pearlescent shimmer that catches light from inside the pour rather than sitting on top of it. Particle size controls whether you get a soft sheen or visible sparkle. Most craft-grade mica is not cosmetic-safe and almost none of it is food-safe. This guide explains how to choose a grade, how to mix it into resin without lumps, and how the colour behaves over time.
What mica powder actually is
Mica is a naturally occurring silicate mineral. Crushed and milled to a fine powder, the flakes are flat and reflective, which is why a sprinkle of it in resin reads as shimmer instead of dust. On its own, raw mica is close to colourless with a soft pearl finish.
The coloured micas sold for craft work are mica platelets coated with a pigment layer (often iron oxide, titanium dioxide, or carmine for the warm tones). The mineral does the optics, the pigment does the colour. That coating matters more than people think: it determines UV stability, opacity, and whether the powder behaves the same in epoxy as it does in UV resin.
A few honest framing notes before going further:
- We do not stock mica as a primary line. Customers usually buy mica from craft pigment suppliers and use it with the resin tooling we do stock (mixing cups, silicone mats, stir sticks, moulds).
- "Mica" on a craft shop shelf often includes pigment-coated mica, synthetic fluorphlogopite (a lab-grown mica analogue), and pearl pigments. They look similar in the jar and behave similarly in resin, so for practical purposes the term covers all three.
Mica vs glitter vs pigment paste
These three colourants are constantly confused. They behave differently in a pour.
Mica powder. Translucent. Catches light from inside the resin. Reads as pearl, shimmer, or soft metallic. Settles slowly. Best for shifting, depth-driven colour.
Glitter. Opaque flakes, usually plastic (PET) or aluminium. Sits visibly in the pour as individual pieces. Reads as sparkle points, not as colour. Will sink to one face unless the resin is thick enough to hold it.
Pigment paste (or pigment drops). Opaque or translucent colour with no reflective component. Blocks light. Reads as solid colour. Best for backgrounds, blocking out a mould, or building contrast under a mica top layer.
The combination most resin artists settle on is pigment paste for the base colour, mica for the shimmer layer on top, and glitter only when the look calls for visible flecks. Layered correctly, that gives depth.
Particle size and what it does
Mica is sold in grades by particle size, usually measured in microns. The grade controls the visual effect more than the colour does.
5 to 25 microns (fine). Reads as smooth pearlescent sheen. No visible flake. Good for soap, makeup-style finishes, and resin work where the goal is colour with a soft glow rather than visible sparkle.
40 to 100 microns (medium). The default for most resin art. Balanced shimmer with reasonable colour saturation. Mixes easily, stays suspended for a normal pour cure time.
100 to 250 microns (coarse). Visible flake. Reads closer to glitter than to pearl, but with mica's translucent quality so it still catches light from inside the resin rather than blocking it. Settles faster, so it is harder to keep evenly distributed in deep pours.
Above 250 microns. Specialty. Often marketed as flake pigments. Used sparingly for accents.
If a supplier does not list particle size, assume medium grade. If you want a specific look, buy from a supplier that publishes the micron range.
How to mix mica into resin without lumping
The single biggest beginner mistake is dumping mica directly into a full cup of mixed resin and stirring. The flakes hit the surface tension, clump, and never fully disperse. You end up with shimmer dots and unmixed dry powder at the bottom.
A reliable workflow:
- Mix resin and hardener first. Get the resin fully combined and rest the bubbles for thirty seconds.
- Decant into a smaller mixing cup. Pour off only the volume you want coloured. Leave clear resin in the main cup for layering.
- Add mica in pinches, not scoops. Start with roughly a quarter teaspoon per 30 ml of resin. Adjust from there. Most crafters use too much.
- Stir slowly with a wide flat stir stick. Press the mica down into the resin rather than swirling it through the surface. Fold, do not whip. Whipping introduces bubbles you will spend ten minutes torching out later.
- Let it sit for a minute and check the rim. Undispersed mica usually shows as a dry ring at the top of the cup. Fold it back in.
- Pour before the resin starts to heat. Once exothermic kicks in, mica tends to settle unevenly.
For dusting moulds (a metallic-finish technique where mica goes directly into the silicone mould before resin is poured), use a soft dry brush and tap off the excess. Too much mica at the mould wall causes a chalky surface instead of a polished metallic look.
Colour stability and UV
Not all mica colours behave the same in sunlight. The mineral itself is stable. The pigment coating is what fades, and which pigment was used decides how fast.
- Iron oxide pigments (most warm and earth tones). Very UV stable. These hold their colour for years even in direct light.
- Titanium dioxide whites and pearl coatings. Stable.
- Organic colourants (some pinks, purples, neons, deep blues). Less stable. A bright pink mica that lives in a south-facing window can shift noticeably within a year.
- Synthetic mica with neon coatings. Often the least stable, marketed for visual impact rather than longevity.
If a piece is going outdoors or into a sunny window, use a UV-resistant resin and lean on iron-oxide-based mica colours. Keep the neons for indoor display work.
Food safety, skin safety, and the disclosure problem
This is where craft-grade mica is most often mishandled.
Food safe. Almost no craft-grade mica is food safe. Even mica that looks the same as a food-grade lustre dust is usually not certified for it. Do not use craft mica on cake decorating, in chocolate moulds, or inside any food-contact resin item.
Cosmetic safe. Some mica is sold as cosmetic grade with appropriate certification. Most is not. Craft-grade mica may contain pigments (notably some iron oxides and lake colourants) that are fine in a cured resin block but not approved for direct skin contact. Soap making with mica is fine when the mica is labelled for that use. Eye makeup needs cosmetic-grade certification specifically for the eye area.
Cured resin. Once mica is fully sealed inside cured resin, the wear surface is the resin, not the mica. Standard food-contact rules for the resin itself still apply, and most craft epoxies are not certified for food contact regardless of what is mixed into them.
The shorter version: assume craft mica is for decorative resin and craft work only unless the label says otherwise.
Safety while handling the powder
Mica is a fine inhalable dust. The mineral itself is not toxic, but any fine particulate is bad for lungs over time.
- Wear a dust mask or respirator when scooping or mixing dry mica.
- Work on a clean surface with the lid of the jar partly on. Mica clings to everything and travels further than you would expect.
- Wipe up spills with a damp cloth, not a dry brush. A dry brush sends it airborne.
- Store jars sealed, away from heat and humidity. Damp mica clumps and loses flow.
Buying tips
Signals to look for when sourcing mica for resin work:
- The seller publishes a particle-size range, not just "fine" or "coarse".
- The pigment family is disclosed for each colour (iron oxide, titanium dioxide, organic, synthetic mica).
- Cosmetic and food claims are explicit. If the label is silent on cosmetic safety, treat it as craft only.
- The colour swatches are photographed in resin, not just dry powder. Dry mica often looks dramatically different from cured mica.
If a listing is vague on those points, expect surprises in the pour.
Frequently asked questions
Q: Can I use mica powder in candles? A: Yes, but it does not bind to wax the way it binds to resin. It tends to settle at the bottom of the candle and the surface shimmer fades after the first burn. Most candle makers prefer dye chips for body colour and reserve mica for the top finish.
Q: How much mica do I need per 30 ml of resin? A: Start with about a quarter teaspoon and adjust. More mica does not mean more shimmer past a certain point; it just means more opacity. The effect plateaus quickly.
Q: Why does my mica look chalky on the surface of a cured piece? A: Either you dusted the mould with too much loose powder, or the mica settled to the bottom of the pour and you are looking at the underside. Mixing thoroughly and pouring before the resin starts to thicken usually fixes the second case.
Q: Is synthetic mica different from natural mica? A: Synthetic mica (sometimes called fluorphlogopite) is a lab-grown analogue with cleaner optical properties and no concerns about natural-mica supply ethics. For resin work, the two behave almost identically. Many premium pigment lines are now fully synthetic.
Q: Can I mix mica with alcohol ink or pigment paste? A: Yes. Mica plus a small amount of translucent pigment paste reads as a tinted pearl. Mica plus alcohol ink works for surface effects but the alcohol can interfere with resin cure if used in large amounts. Test on a scrap pour first.