If a New Wax Wins on Appearance but Requires Complete Wick Retesting, How Do I Include Development Cost in the Switching Decision?

Add development cost to the switch as a one-off, then divide it by the saving per candle

A wax change reopens the wick question. Different waxes melt, pool and draw fragrance differently, so a wick that was right in your old wax can be too small or too large in the new one, and the only way to know is to burn-test a bracket of wicks in every jar you sell. That work has a real cost — test materials, burn-monitoring hours and calendar weeks — and it is paid once, before the first saleable candle in the new wax. The clean way to include it is to treat it as a one-off development cost and ask how many production candles it takes for the per-candle saving to pay it back.

Payback in candles = development cost ÷ net saving per candle. The development cost is everything you spend to approve the new wax: the wick bracket in every jar size, the oils you must confirm, and the time to watch the burns. The net saving per candle is what the better appearance is worth — fewer candles hidden, discounted or scrapped — minus any increase in material cost. If the net saving is positive and the payback is a fraction of a few months' production, the switch is worth it. If the saving is thin, a long development programme can make the better wax a worse business decision.

The worked example is a maker selling three clear SKUs in CSI 464 — a Mini 40 ml jar, a Yankee 130 ml jar and the Clear 150 g jar — who finds Premium Coconut Soy Wax CSI 468 wins on appearance. Every figure that is not a CSI price is a labelled example for you to replace: the share of candles currently failing appearance, the new wax's share from your own pilot, labour rates and volumes. CSI publishes no adhesion or reject data for either wax, and nothing here says CSI 468 adheres better than CSI 464; the example simply assumes your own pilot said so.

Sizing the wick retest: jars × oil families × wicks × candles

The size of the development programme is a multiplication, and it is worth writing out because it grows quickly. The example tests every jar size you sell (3), with the lightest and the most demanding oil in the range (2 — Lemongrass and Lime and Dark Vanilla Oud), across a bracket of 3 wick types, 3 candles each: 3 × 2 × 3 × 3 = 54 burn candles. Testing the lightest and heaviest oils first, rather than every oil, is a common way to bracket the range; the remaining oils then get a short CONFIRM on the winning wick. Stress-testing the hardest fragrance explains the logic.

The wick bracket here is Eco Candle Wicks Thin C1, Eco Thick C2 and Cotton Braided Wicks Ready Made. CSI publishes no wick size for any jar and no CSI wick is claimed to be a size step from another, so these are three constructions to compare, not a ladder. Your current wick in CSI 464 should be one of the three, so the bracket starts from what you know. CSI 468's page states a 58–60°C pour, which is a process change in itself: write it on the batch sheet and expect tops and adhesion to need a quick look at the new temperature.

The development cost, priced

Here is the full development kit priced with listed, in-stock CSI packs. The 4,775.9 g of CSI 468 is cheapest as 1 × 5 kg at ₹3,185.00 (as 500 g and 1 kg bags it would be ₹3,250.00). Each oil needs 207.6 g across the three jar sizes.

Two costs are not in that table because they are yours to value. The first is calendar time: pour, cure, four burns per candle and a CONFIRM round on the remaining oils is several weeks during which the new wax cannot be sold. The second is the risk that the bracket finds no acceptable wick in one jar, which sends that SKU back to the start. Put a figure on both if your season makes them matter — before Diwali on Sunday 8 November, calendar time is usually the larger cost.

The saving per candle — and why material cost can eat it

Work it per candle in the Clear 150 g SKU. With Dark Vanilla Oud at the 1 kg rate, an example Eco Thin C1 wick at ₹5.90 and the ₹94.40 jar, the CSI materials are ₹238.61 in CSI 464 and ₹256.50 in CSI 468 at 5 kg wax rates — CSI 468 adds ₹17.88 a candle. Add a labelled example of ₹60.00 for labour and packaging. If spotted candles are effectively lost (scrapped, or sold at so deep a discount that their margin is gone), the cost of each full-price candle is the total divided by (1 − failing share). With a labelled example of 15% failing in CSI 464 today, that is ₹351.31 per full-price candle.

The pattern is the useful part. If your pilot shows the new wax failing on 3% of candles, each full-price candle costs ₹25.02 less and the development pays back after about 578 candles. At 8% the saving shrinks to ₹7.29 and payback stretches to 1,985. And there is a break-even: if the new wax fails on more than 9.9% of candles, its higher material cost eats the whole appearance gain and the switch never pays back. That is why the pilot's acceptance plan matters so much — the payback is only as good as the reject rate you measured.

The table assumes failing candles are lost. If you hide them behind an opaque label or sell them as seconds instead, the saving per candle is the label cost or the discount avoided, which is usually smaller — the label-cost post and the discounts-and-complaints post price those treatments. Run the payback with whichever treatment you actually use.

What to buy, in what order

Buy the development kit first — it is the only purchase the decision needs. Production quantities of CSI 468 and of any new wick wait until the bracket has a safe winner in every jar and the pilot has measured the reject rate. If one jar size has no acceptable wick, keep that SKU in its current wax rather than holding up the others; running two waxes is a labour cost, but it is smaller than a failed SKU.

The decision rule

Apply from the top. The rule deliberately looks for reasons not to switch before it approves one, because a switch is the only option here with a large one-off cost. The wax-switch payback post covers the simpler case with no wick work; the retesting post lists everything a blend or wax change reopens.

The CSI products in this retest

Where this fits in the qualification

This page owns development cost in the switching decision. The scorecard decides whether the new wax wins; the pilot and the acceptance plan measure the reject rate the payback depends on; the SOP locks the new wick and pour temperature; and the series capstone shows where development sits in the path to a bulk order.

Frequently asked questions