Custom Candle Manufacturing: Wax, Wicks, Scent and Burn Tests

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Candles look like one of the easiest products to launch. Wax, a wick, a jar, a nice label. Done.

Then the first customer review comes in: "Smells amazing, but it tunnelled after two burns." Or worse: "The jar cracked."

A candle is a small fire in a glass. Getting it right is mostly about testing, not design. Here's how custom candle manufacturing actually works, and what to check before you order.

Step 1: Choose your wax

The wax decides how the candle burns, how well it holds scent, and how it looks.

Wax	Good points	Watch out for
Soy	Natural story, soft creamy look	Can "frost" (white marks), softer in heat
Paraffin	Strong scent throw, smooth finish, low cost	Some customers avoid it
Coconut blends	Smooth, clean look, good scent	Higher cost
Beeswax	Natural, long burn	Expensive, its own smell, harder to scent
Blends (e.g. soy-paraffin)	Balance of cost, look and scent	Be honest in your marketing about what's inside

Tip: decide what you'll say on the label first ("100% soy", "natural wax blend") and then pick the wax. Your claims must match the real recipe.

Step 2: Match the wick to the candle

The wick is where most candle problems start.

• Too small: the candle "tunnels." It burns a hole down the middle and wastes wax around the edges.
• Too big: the flame is too high, the candle smokes, and the jar can get dangerously hot.

The right wick depends on jar diameter, wax type, fragrance and dye. Change any one of those and the wick may need to change too. Cotton wicks are most common. Wooden wicks give a crackle and a different look, but need their own testing.

Step 3: Get the fragrance load right

The fragrance load is how much scent oil goes into the wax, usually shown as a percentage. Many candles sit somewhere around 6 to 10%, but every wax has its own limit.

More isn't always better. Too much oil can:

• Sweat out of the wax ("oiling")
• Make the candle burn badly or smoke
• Clog the wick

Ask the supplier for the fragrance supplier's safety data sheet (SDS) and IFRA certificate. You'll need them for your labels (see Step 6).

Step 4: Test burns (the step people skip)

Never approve a candle from a photo. Burn it. Several times.

A simple test burn:

1. Light the candle and let it burn until the melt pool reaches the edge of the jar. A common rule is about one hour per inch (2.5 cm) of diameter.
2. Check the flame height, smoke and soot.
3. Let it cool fully. Repeat a few times.
4. Burn one candle all the way down. Check how hot the glass gets near the end.

What you want to see: a full melt pool, a steady flame, little soot, and no tunnelling.

Test samples from the real production wax, wick and fragrance, not a lab version. Then test a few pieces from mass production again.

Step 5: Choose the right container

Not every pretty glass can handle heat.

• Use glass made for candles, with even thickness and no bubbles or cracks
• Check the jar from every new batch. A cheaper glass supplier can change everything
• Lids, wooden tops and metal tins all need checking for fit and finish
• Make sure your label can handle a little heat and won't peel

Step 6: Safety labels and rules

Candles need safety warnings. What exactly depends on where you sell.

• US: the industry follows ASTM standards for candle fire safety and warning labels (for example ASTM F2058 for labels and ASTM F2417 for fire safety)
• EU: there are European standards for candle safety labels (EN 15494), soot (EN 15426) and fire safety (EN 15493). Scented candles may also need CLP hazard labels because of what's in the fragrance oil
• Most markets want burning instructions: trim the wick, never leave it unattended, keep away from children and pets

Rules change and differ by country. Check the current requirements for your market with a testing lab or compliance expert before you print labels.

Step 7: Packing and shipping

Candles and heat don't mix. A container sitting in the sun can get very hot inside.

• Ask the factory about the melting point of your wax
• Plan sea shipments around hot months if you can, or choose a higher melt-point blend
• Use inserts or dividers so jars don't knock into each other
• Do a drop test with a fully packed carton before you approve the packaging

MOQ and timeline

Stock jars with your own label and scent often start at a few hundred units per scent. Custom jars, custom colours and custom packaging push the minimum up. Plan a few weeks for sampling and test burns, then production and shipping. Give yourself extra time before the holiday season. Candles sell most in Q4, so factories get busy early.

The bottom line

A great candle is a tested candle. Choose your wax, match the wick, keep the scent load sensible, burn it more than once, and get the labels right for your market. That's what turns "smells amazing" into "bought it again."

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