Two facts about scent that decide whether a candle range works, and neither appears on a normal quote.

The ceiling

Wax will only hold so much fragrance oil. The figure varies by wax, but it exists and it is physical.

Below it, more oil generally means more scent. Above it, the oil stops binding: it sweats to the surface, the wax looks greasy, the flame gutters and the hot throw actually gets weaker. It is one of the few places where the intuitive answer is exactly backwards.

Cold throw and hot throw are different things

Cold throw is how it smells unlit in the jar. Hot throw is how it fills a room while burning. They are not proportional, and a candle can be strong at one and weak at the other.

Judge a candle on the one that matters for its use: retail shelf appeal is cold throw, a hotel lobby is hot throw.

Cure time

Soy needs days in the jar for the oil to bind into the wax. A candle assessed straight after pouring will smell weaker and slightly raw compared with the same candle a week later.

So samples should be cured before they are judged, and production should not be rushed to hit a date by shipping green.

What to ask for in writing

The wax, the fragrance percentage, the wick size and the measured burn time, recorded per SKU.

That document is what makes a reorder in two years smell like the original rather than like a fresh guess.