I Added Mica to a Decorative Candle Formula That Previously Burned Well — Could This Change Wick Performance Enough to Require Retesting?

Why mica is not like dye

Candle dye is meant to dissolve into the wax and fragrance and travel with them. Mica is a mineral pigment — fine, shimmering particles that stay particles. They do not dissolve in wax, and they do not burn away in the flame the way wax and fragrance do. General candle-making practice commonly cautions that pigments such as mica can clog a wick if they are melted into the burning pool: the wick draws up liquid wax and, with it, whatever is suspended in that liquid. Particles that cannot burn are left behind in the wick. That is a caution, not a measurement — CSI has not burn-tested its mica, publishes no burn data for it, and will not tell you it is safe or unsafe in your pool. It tells you to test.

The second row surprises people. Mica dusted on the top of a container candle looks like decoration that sits apart from the burn, but the top is the first part of the candle to melt. On burn one, the surface shimmer is in the pool. The amount is smaller than mixing it through, so the effect may be smaller — but the particles still reach the wick, and a small amount accumulating over a few burns is exactly how a wick clogs gradually. Only mica that the pool never touches is outside the combustion system.

So, is a retest really needed?

Yes, if the mica is in the wax or on the top — and it is the more serious kind of retest. A dye change at a matched shade is usually a confirmation. Adding a non-dissolving pigment to a pool that previously carried none is a new material in the combustion path, so this page treats full-life burning as REPEAT, not CONFIRM. The good news is that it is also the kind of change you can often avoid rather than validate: moving the shimmer to the outside of the pool keeps the look and keeps the old approval.

The things that stay valid are the same as for any colour change. The wax, fragrance, load, fill and wick size were approved without mica and nothing about them has changed. Your old candle is therefore the ideal control: pour it exactly as before, beside the mica versions, and let the comparison show what the mica does. What you should not do is judge the mica candle alone. A single shimmer tin that burns acceptably tells you nothing about whether it burns as well as the tin you used to sell.

The retest matrix for adding mica

The test protocol: ten tins, three placements

Each tin is 85 g finished — the one published fill in CSI's container range — made of 6.8 g of Japanese Cherry Blossom and 78.2 g of CSI 468 at 8%. Use the same amount of mica per tin in groups B and C that your decorative recipe uses; CSI publishes no mica dose, so the amount is yours. Three tins per group is a labelled working practice, plus one extra B tin for cutting. A fourth placement — mica on the lid or the tin's outside — needs no burn test at all, which is the point of the next section.

The scoring sheet

Every line compares a mica tin with the no-mica control. CSI publishes no numeric flame-height or jar-temperature limit, and aluminium tins get hot to the touch in any candle, so the tin-side reading is judged only against the control: a line passes when B and C are no worse than A, within your container supplier's guidance and the fire-safety standard you work to (ASTM F2417 is a commonly cited US example).

The priced test kit

Ten 85 g tins with a 5% pour-loss allowance (a working assumption) need 892.5 g of finished candle: 821.1 g of wax and 71.4 g of oil at 8%. Wax, oil and mica are CSI live pricing pulled 24 September 2026; tins, dyes and mica from the same catalogue pull; wicks are Blog 760's verified figures with packs rechecked on 25 September 2026.

CSI 468 costs the same as 1 kg (₹650.00) or 2 × 500 g (₹650.00), so take whichever you prefer. For the oil, 50 g + 2 × 15 g gives 80 g for ₹478.00; a single 100 g is ₹500.00 and 2 × 50 g is ₹540.00. The tins come in a pack of 12 at ₹30.00 each, which leaves two spare. The material cost of one production tin at these test-pack rates is ₹123.45 before mica — ₹50.83 wax, ₹36.72 oil, ₹30.00 tin, ₹5.90 wick — excluding labour, packaging, freight and GST.

Decision rule: fix the placement before the wick

Notice that "use a bigger wick" is not on the list. A larger wick might burn through a clogging wick head for longer, but it makes a hotter candle to carry a decorative ingredient — and in a metal tin that is a poor trade. If the mica cannot pass in the pool, keep it out of the pool. The hotter-jar post explains why a more aggressive burn is never a fair price for an extra feature.

Release and record

Mica sits alongside the other colour changes in this cluster: a dye brand swap, a stronger dose and a change of dye form. It is the one most likely to need a full-life test, because it is the one ingredient that does not dissolve. The significance checklist places mica-in-the-pool in the revalidation tier and mica-outside-the-pool in the no-test tier — the same ingredient, two very different changes.

Finally, record placement as carefully as amount. "0.5 g mica" means one thing mixed through and another brushed on top; a future employee reading only the amount could move it back into the wax without knowing it was tested out. The documentation post covers writing down why a formula changed, so the reason survives the person who made the decision.

Frequently asked questions