My New Wick Shipment Looks Slightly Thicker Than the Previous Batch Even Though I Ordered the Same Size — Should I Repeat Burn Testing?

Looks thicker versus is thicker

When a new shipment of the same wick arrives looking chunkier, there are several explanations, and only some of them matter for the burn. The braid itself may be heavier, with more or thicker fibres. The priming wax coat may be heavier, which fattens the look but may burn off quickly. The wicks may have been packed flatter or looser, so they spread differently in your hand. Or you may simply be remembering the old lot as thinner than it was.

Check the paperwork before the caliper

Before measuring anything, confirm that you actually received what you ordered. Put the old invoice and the new invoice side by side and compare the product name and the size or thickness option exactly as written. Do the same with any packet labels. A thin option picked as a thick one, or a size code that changed on the supplier's side, explains a thicker wick in thirty seconds and needs no burn at all, just a corrected order.

The first job at goods-in is to separate these. You cannot do that by eye alone, and you cannot do it without something to compare against. That is why retained old-lot pieces are so valuable: they turn a vague impression into a measurement.

How to measure without fooling yourself

Braided cotton is soft. Close a caliper firmly and you measure how far you squashed it, not how thick it is. Close it just until the jaws touch, and do it the same way every time. If you can, let the same person take every reading in the comparison.

Now look at the numbers. The question is not whether the new average is higher. It is whether the new readings fall outside the range the old lot already showed. Natural fibre products always vary a little piece to piece. If the new lot overlaps the old lot's spread, you are looking at normal variation. If almost every new reading sits above the old maximum, the lot really is different.

If the numbers differ: a targeted burn, not a full re-test

A full revalidation, every jar, every oil, burned to the end, is a large job. It is justified when you know something important changed. It is not the right first step when all you know is that a caliper disagrees.

Instead, choose the jar and oil combination where your current wick is already working hardest: the widest jar you use that wick in, or the oil that already gives you the largest flame. If the thicker lot is going to cause trouble anywhere, it will show there first. Pour that combination with old and new wicks from the same melt, same pour temperature, same cure, and burn them side by side, attended, in a still room. Watch flame height, melt pool speed, mushrooming and soot on the glass.

Decide before you light anything what would count as a difference. Write it down: for example, a flame that is visibly taller in every paired comparison, a melt pool that reaches the wall a full burn earlier, repeated mushrooming where the old lot had none, or soot on the glass. Criteria written after the burn tend to bend towards the answer you hoped for. Criteria written before it keep you honest.

Worked example: the cost of checking versus the cost of guessing

Say you pour 150 g candles in the clear 150 gram apothecary jar, using CSI 468 coconut-soy wax and Citrus Lemon at 8% of total candle weight, with a ₹5.90 wick. You plan a 300-candle run next week.

A targeted burn of three old-lot and three new-lot candles costs 6 × ₹222.19 = ₹1,333.14 in materials. The run you are protecting is worth 300 × ₹222.19 = ₹66,657.00 in materials alone. If the thicker wick turns out to over-fire in that jar, the test has just saved you from pouring the run and then deciding what to do with it.

Equally, if your measurements show the lots overlap, skip the burn and use the money elsewhere. Do not pay for a test the evidence does not ask for.

Deciding, releasing and recording

Once the evidence is in, the decision usually falls into one of four outcomes. Measurements overlap: release. Measurements differ but the targeted burn matches the old lot: release with a note to watch the first production burns. Burn differs within acceptable limits: conditional release, perhaps only for jars where the wick has headroom, which means a fresh qualification for those jars rather than a shortcut. Burn differs beyond your limits: quarantine and talk to the supplier.

For the supplier conversation, send your measurement log, a photograph of old and new pieces side by side against a ruler, and your burn notes. Ask directly whether the construction or the coating changed between orders. CSI product pages do not publish wick dimensions or tolerances, so if you bought from us, ask on WhatsApp (+91 7397976926) and write the answer into your goods-in record. The same applies to any supplier: an answer you did not record is an answer you will not have when the next lot arrives.

Whatever the outcome, keep the two lots apart on the shelf and on the batch sheet. If you finish the old wicks midway through a run and carry on with the new ones, split the run into two batch codes at that point. Mixing lots inside one batch code means that if customers later report a difference, you cannot tell which wick they got. Use the older approved lot first, and let the new lot start a fresh batch.

Finally, bag and label ten or so pieces of this new lot before production uses them up. The next time a shipment looks different, you will have something real to measure against.

Where this page fits

CSI already has guides that cover parts of this question. This page covers the goods-in check for the question above; these go deeper on the rest:

Three things to buy for this job

Frequently asked questions