Custom cooler bags: which format fits, and what should you check?
A good cooler bag is still being carried months later. Four choices get you there: the format, the cold, the liner and the decoration.
Start with what goes inside
According to ASI, the promotional products industry association, usefulness is the top reason people keep a promotional item (U.S. findings) [1]. Starting from the use is often the safest bet: a lunch bag for the office or a new-hire welcome kit, a can cooler for event drinks, a strap-carry bag for anyone on the move.
A "24-can" bag won't necessarily keep 24 cans cold: some manufacturers count room for ice, others don't [2]. For a lunch bag, check that it fits the usual containers without much empty space: in a Reviewed test, extra air made the cold harder to hold [3].
For a company outing, follow Health Canada's advice: pack food and drinks in separate coolers; the food cooler, opened less often, stays cold longer [4].
What a soft cooler can realistically promise
Two independent tests agree: soft coolers hold ice for less time than hard coolers, but measured durations vary widely from one test, and one bag, to another [2][5]. Don't promise a duration; for several days or full sun, a hard cooler is generally better insulated.
America's Test Kitchen (ATK) found that closed-cell foam slows heat and thickness helps, yet some open-cell foams did nearly as well [5]: advertised insulation is a clue, not a promise. Kept in the shade and opened sparingly, a bag holds the cold better [4].
Liner, zipper and care
Manufacturers quoted by Practical Sailor name a punctured waterproof liner as one of the most common warranty issues: meltwater seeps into the shell and leaks through the seams [2]. So look for a continuous liner, easy to check and wipe clean; it touches food, so ask for its declarations of compliance [12][13]. Test the zipper: according to ATK, one that snags discourages people from opening the bag [5].
Health Canada recommends washing lunch bags in hot soapy water after each use [6]; they should then dry completely, left open, to prevent odours and mould [5][7]. Care instructions handed out with the bag help keep it in use, and your logo with it.
Decoration: protect the insulation, plan the placement
SanMar's guide for decorators (SanMar distributes blank bags) advises against embroidering through the insulation: the needle punctures the fabric and can cause leaks [8]. Embroidery therefore goes on a non-insulated outside pocket, which limits its size. A transfer heat-pressed at high temperature can also crush the insulation [8].
On water-repellent coated nylon, ink may adhere poorly or scratch off, according to McLogan Supply, a screen printing supply distributor [9]; heat transfer manufacturer Stahls' recommends a test, given the range of fabrics and coatings [10]. Before a big order, confirm how the logo will hold up.
According to one distributor, promotional cooler bags are usually printed on the front, the strap or both, with the imprint area growing with bag size [11]. Have a compact version of your logo ready.
Écran Blanc's advice
For an employee gift or welcome kit, go with a lunch bag with a continuous liner and a smooth-running zipper, handed out with its care instructions. For a tournament or team outing, pair a shared drinks cooler with individual lunch bags. And check the logo placement on the proof.