Shrink bands and caps
Updated
The band is tamper evidence, a moisture barrier of sorts, and a piece of shelf presentation, in that order of usefulness.
What a band does
A perforated shrink sleeve over the cap and neck that has to be broken to open the tube.
It signals unopened, holds the cap on in transit, and makes a hand-made product look finished. On a market table it is the difference between a stall that looks like a business and one that looks like a hobby.
Sizing one
Bands are specified by lay-flat width and length, and the width has to suit the diameter of the tube plus the cap.
Too wide and it will not shrink down evenly, leaving a wrinkled collar. Too narrow and it will not go on. Buy a sample before a case; the tolerance is real.
Perforated is worth the small extra, because a band the customer has to attack with a fingernail is a bad first impression.
Applying them
A heat gun on low, turning the tube, from a distance rather than close. A hair dryer works and is slow.
Too much heat softens the tube underneath and can soften the balm. Move continuously and stop as soon as it is tight.
Do it after labeling and after the balm is fully set and cold.
Whether you need one
Not required on an ordinary cosmetic lip balm, and worth having anyway for wholesale, where a buyer reads it as a sign the maker knows what they are doing.
At a market where every unit is handled, it is doing a real job: it tells a customer that the tube they are holding has not been opened by the four people before them.