A Candle Is a System, Not a Container
Candles look like the simplest home fragrance format and are in practice the most technically demanding. Wax, wick, fragrance load and vessel are interdependent: change any one and the burn behaviour of the whole product changes.
The consequence is that a candle cannot be specified the way a diffuser or spray can, then filled. It has to be burn tested as an assembled combination.
| Wax and wick | Different waxes need different wick sizes to achieve a full, even melt pool. |
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| Vessel diameter | Determines the melt pool the wick must reach. A wider vessel may need a larger wick or multiple wicks. |
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| Vessel material and thickness | Affects heat retention and the vessel's external surface temperature during burn. |
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| Fragrance load | Affects both scent throw and burn behaviour. More fragrance is not simply better. |
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| Fragrance composition | Some materials behave differently in wax than in an alcohol or oil base. |
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This is why candle projects run longer than other home fragrance formats. Burn testing is not an optional check at the end — it is how the specification is arrived at, and it takes time that cannot be compressed.
Wax Direction
Wax choice affects appearance, burn characteristics, scent throw and positioning. Each has trade-offs rather than a clear winner.
| Direction | Characteristics | Considerations |
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| Soy and vegetable | Natural positioning, softer appearance, slower burn | Surface finish can be uneven; may frost or show wet spots against the glass |
| Paraffin | Smooth finish, strong throw, well-understood behaviour | Petroleum-derived, which conflicts with some brand positioning |
| Coconut and blends | Smooth surface with natural positioning | Higher material cost |
| Beeswax | Natural, distinctive character of its own | Its own scent competes with added fragrance; higher cost |
| Blends | Tuned to balance finish, throw and cost | The most common commercial approach |
"Natural wax" positioning is worth interrogating early. Vegetable waxes can produce surface irregularities that are normal to the material but read as defects to customers, so the marketing claim and the visual expectation need to be aligned before production.
Wick Selection and Burn Testing
The wick is the smallest component and the one most likely to cause a product failure. It is selected by testing rather than by specification.
- Undersized wick — tunnelling. The candle burns down the centre, leaving wax on the walls and wasting most of the product.
- Oversized wick — excessive flame, sooting, and a vessel that becomes too hot.
- Wick type — cotton, wood and other constructions burn differently and produce different aesthetics; wood wicks have a characteristic sound some brands want.
- Multiple wicks — wide vessels may need two or three to achieve an even melt pool.
- Centring and securing — an off-centre wick burns unevenly and can overheat one side of the vessel.
Burn testing evaluates melt pool formation, flame height, sooting, vessel temperature, scent throw both unlit and lit, and behaviour across successive burns. It is the stage that determines whether a candle specification is viable, and it cannot be shortened by wanting it to be.
Vessel and Packaging
| Vessel | Glass, ceramic, tin or concrete. Diameter drives wick selection; material and thickness affect heat behaviour. Also the object that remains in the customer's home. |
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| Lid | Protects from dust and adds gift value. Material and fit are separate decisions from the vessel. |
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| Dust cover | A lower-cost alternative to a lid for retail protection. |
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| Label | Must carry required safety text alongside branding — typically the tightest layout constraint in the category. |
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| Base label | Commonly used for warnings and burn instructions, freeing the front label for brand design. |
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| Retail or gift box | Candles sell heavily as gifts, and presentation carries much of the value. |
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| Carton | Weight and fragility mean transit protection needs real attention. |
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Safety Text and Testing
Candles carry more safety obligation than any other home fragrance format, because the product involves an open flame in the customer's home.
- Burn instructions — first burn duration, maximum burn time, trimming the wick, and when to stop using the candle.
- Safety warnings — never leave unattended, keep away from children and pets, keep clear of flammable materials, burn on a heat-resistant surface.
- Stop-use indication — the remaining wax depth at which the candle should no longer be burned.
- Fire-safety marking requirements vary by destination market.
- Testing requirements may apply depending on market and channel.
- Vessel temperature is part of safety assessment, not only comfort.
Availability, production path, testing scope and documentation for candle projects require confirmation for the specific product and destination market. This category carries requirements that fragrance-only projects do not, and they should be raised at enquiry stage rather than after a specification is fixed — see the documentation guide.
What to Confirm
| Product | Fragrance direction, vessel, wax direction, wick, fill weight and SKU count. |
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| Packaging | Label, dust cover, lid, retail box, gift box, insert and carton plan. |
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| Review | Safety text, document needs, destination market and testing or compatibility requirements. |
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Candle FAQ
Why do candle projects take longer than other home fragrance products?
Because burn testing is how the specification is arrived at, not a final check. Wax, wick, fragrance load and vessel are interdependent, so the combination has to be tested across successive burns for melt pool, flame height, sooting, vessel temperature and scent throw. That time cannot be compressed.
Which wax should I choose?
Each direction trades off differently. Soy and vegetable waxes support natural positioning but can show frosting and wet spots; paraffin gives a smooth finish and strong throw but conflicts with some brand claims; blends are the common commercial compromise. Align the marketing claim with the visual result before production.
What causes a candle to tunnel?
Usually a wick undersized for the vessel diameter and wax, so the melt pool never reaches the walls. It can also result from short first burns by the user, which is why first-burn guidance appears on the label. Wick selection is settled by burn testing.
Can my perfume fragrance be used in a candle?
The scent direction can often be translated, but a candle needs a fragrance suitable for use in wax, and some materials behave differently when heated than in an alcohol or oil base. Both suitability and the resulting throw are confirmed through testing on the actual combination.
What safety text does a candle label need?
Commonly burn instructions, safety warnings, a stop-use indication and market-specific fire-safety marking. It takes substantial label area, which is why warnings are often placed on a base label so the front can carry brand design. Requirements are confirmed per destination market.
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