Wet spots
Updated
Patches where the wax has pulled away from the glass, looking like damp. The commonest cosmetic complaint in soy container candles and almost entirely unavoidable.
What they are
Air gaps between the wax and the vessel wall. Light passes differently through the gap, so it reads as a wet patch or a cloudy blotch.
They can appear straight after pouring, or a week later, or after a candle has been warm and cooled again.
Why they happen
Wax shrinks as it cools and glass does not. Adhesion between the two is imperfect, and where it lets go you get a gap.
Natural waxes shrink more than paraffin, which is why soy candles show this and paraffin ones mostly do not.
Temperature cycling is what brings them back after they have gone: a warm shop window, a cool night.
What actually helps
Warming the vessels before pouring, so the wax does not chill against cold glass.
Pouring at the lower end of the recommended range.
Cooling slowly and evenly, in a draft-free place at stable room temperature.
Nothing eliminates it in a natural wax. Anyone who says their process removes wet spots entirely is either using a paraffin blend or has not shipped through a summer.
Whether to worry
It has no effect on burn, scent, safety or quality. It is purely optical.
So the real decision is how to talk about it. A line on the care card explaining that separation between wax and glass is a normal feature of natural wax turns a complaint into a point of confidence, and it costs nothing.