Candles get specified on fragrance and vessel. The two nobody asks about are the two that decide whether it burns properly.

Ask how the wick was sized

It should be a calculation against the internal diameter of the vessel, the wax and the fragrance percentage — then confirmed by a test burn.

If a supplier cannot describe that process, they are using a house default. That is exactly how you end up with a candle that tunnels or a tin too hot to hold.

Ask for the fragrance percentage, and accept the ceiling

Every wax has a maximum load it will hold. Above it the oil sweats out, the flame misbehaves and the hot throw gets weaker.

A supplier who agrees to any number you ask for is not respecting the wax, and the problem shows up after the candles are boxed.

Match the wax to the format

Container waxes are soft and hold fragrance well. Pillar waxes are harder, hold less, and have to be structural because there is no jar holding them up.

A soft wax pillar will slump in a warm room before it is ever lit.

Build cure time into the schedule

Soy needs days in the jar before the fragrance binds. Test a candle on day one and you are testing a different product from the one your customer will open.

Any supplier offering to skip this to hit a date is offering to ship you a candle that smells wrong.

What to send when you ask for a quote

Fragrance brief, vessel preference, quantity, and where the candle gets used — retail shelf, dining table, treatment room. That last answer often changes the fragrance load more than anything else.