My Current Soy Wax Costs Less but I Lose 5% of Production to Defects — Would a More Expensive Wax with Fewer Rejects Actually Improve Margin?

Margin improves only if you can sell the candles you stop losing

The question has two answers depending on one fact about your business. If you are demand-limited — you sell a fairly fixed number of candles a month and could pour more if you wanted — then fewer rejects only save the materials and labour of the candles you no longer scrap. A dearer wax has to win on cost per saleable candle, and that is hard. If you are capacity-limited — you sell everything you can pour, so pouring time is the constraint — then every reject you avoid is an extra candle to sell, and the dearer wax wins whenever the margin on those extra candles outweighs its extra cost.

Worked with real CSI materials: a 200 g candle at 8% with Fresh Strawberries Fragrance Oil costs ₹226.70 in Luxury Soy Wax CSI 464 and ₹250.55 in Premium Coconut Soy Wax CSI 468 at 5 kg rates — ₹23.85 more per poured candle. Your current CSI 464 loses 5%; suppose the candidate loses an example 1%. On cost alone the dearer wax cannot win: even with zero rejects its candle costs more than CSI 464 after its 5% losses. But if you are capacity-limited, the four extra saleable candles per hundred poured are worth their selling price, and the dearer wax pays when you sell above about ₹656.16 (with an example ₹60.00 of selling costs per candle).

Neither CSI wax is claimed here to produce fewer defects than the other — CSI publishes no defect data, and the candidate's rate is an illustration. Your 5% is your figure, used as given. The point is the structure of the decision, which holds for any pair of waxes: know whether you are selling against demand or against capacity, then compare margins, not costs.

Margin per candle at ₹499 and ₹799

Start with the per-candle view, which is the demand-limited one. Cost per saleable candle here is materials plus an example ₹15.00 of production labour per poured candle (lost on rejects too), divided by (1 − reject rate). Selling costs — an example ₹60.00 for packaging, label and payment fees — are added only to candles that sell, because rejects are caught before packing. Gross margin is shown both ways, so there is no confusion: gross margin % is profit ÷ selling price; markup % is profit ÷ cost.

Per candle, the current wax keeps more margin at both prices: its 5% losses add less than the ₹23.85 the dearer wax adds to every poured candle. If your month is demand-limited, that is the answer — stay on the cheaper wax and work on the 5% through process. The reject budget shows how many rejects the cheaper wax can carry before this flips, and the heat-gun post covers rescuing the ones you can.

The month view: demand-limited against capacity-limited

Now the whole month, both ways, with every volume an example. Demand-limited: you sell 380 candles and pour what that needs on average. Capacity-limited: you can pour 400 candles and sell every one that passes.

Three of the four cells favour the current wax. The fourth — capacity-limited at ₹799 — favours the dearer one, because 16 more saleable candles a month at ₹799 are worth more than 400 × ₹23.85 of extra wax. The break-even selling price for that scenario is ₹656.16; above it, fewer rejects improve margin, below it they do not. In general: S* = (extra material per poured candle ÷ reject-rate improvement) + selling costs per candle. Labour cancels in the capacity case because both waxes are poured the same number of times.

Proving the candidate's defect rate: why 12 candles are not enough

Your 5% comes from production records — good. The candidate's rate has to come from production too, because small tests cannot separate rates this close. In twelve candles, a 5% wax and a 1% wax both usually show zero or one reject. Even in 100, chance plays a part: if you set the rule "adopt the candidate only if it shows 2 or fewer defects in 100", a wax that truly runs at 5% would still pass about 12% of the time, and one that truly runs at 1% would pass about 92% of the time. That is a reasonable rule for a decision of this size; a tighter one needs more candles.

The priced production split

100 candidate candles. Your CSI 464 production continues as normal and is not priced here. Wax: 18,400 g, 19,320.0 g with a 5% pour-loss allowance (a working assumption). Oil: 1,600 g (1,680.0 g).

CSI 468 for 19,320.0 g is cheapest as 1 × 10 kg + 1 × 5 kg + 4 × 1 kg + 1 × 500 g (₹12,480.00); two 10 kg bags would be ₹12,740.00 and leave about 0.7 kg spare for production. Fresh Strawberries has a real per-gram step (₹3.78 at 100 g, ₹3.54 at 500 g and 1 kg), so the larger bottles are the cheapest way to cover the split. Every candle that passes inspection is sold as normal, so the real cost of the trial is the candidate's defects and the record-keeping.

The decision rule, ending in a purchase

With the example — capacity-limited, selling at ₹799, candidate passing with 1 defect in 100 — the purchase is Premium Coconut Soy Wax CSI 468 in 5 kg bags at ₹3,185.00: 400 candles a month need 73.60 kg of wax, so 15 bags. The example month gains ₹2,285.44 over CSI 464. At ₹499, or in a demand-limited month, the same split result would still leave Luxury Soy Wax CSI 464 as the better buy. How much of a ₹799 price wax should take and the true commercial cost of a soy wax carry this into full pricing.

Margin is where the cost lines of this cluster end up. The cost-per-saleable-candle hub gives the formula; the 1,000-candle rework comparison shows the hours a defect rate eats; the consistency ledger prices order buffers and late complaints, which a margin view should include for branded orders; comparing waxes at their optimal loads adds the fragrance line; and whether easier pouring justifies a dearer wax looks at defects caused by people rather than wax.

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