OK, I will admit that I do make my own labels. I have nothing against gear, I have used him in the past, but making my own allows me unlimited prototyping and super fast (overnight) turn around times (+ I can make whatever I want).
In addition to a printer, the only thing you need to make your own labels is a vinyl cutter. I would recommend a GCC model with enhanced AAS (the vinyl printing term for "creating labels" is "contour cutting").
For the printable vinyl most of the "premium" vinyl is 100 microns (5.5 mills) thick. Yes, you can get thinner/cheaper printable vinyl. I would suspect gears un laminated labels are 5.5 mills thick. (FWIW I use Oracal 1917)
I know most of the people here are familiar with gears "lamination" options but in the vinyl sign industry you generally are looking for how much abrasion & UV protection (none to multi year) in addition to finish (gloss or matte).
In the Oracal line, the "cheap" laminates (they are less expensive) have the least durability (to abrasion & UV)
Oracal Oraguard 236 - 1 year UV, 2.5 mil thick
Oracal Oraguard 210 - 2 year UV, 2.5 mil thick (I use this at a min)
Oracal Oraguard 215 - 5 year outdoor UV, 2.75 mil thick
and there are higher end options from here (they have 8 year laminates).
OK, so a 5.5 mil label with even the thinnest laminate, 2.5 mil is 8 mil total; therefore 8.3 mil sounds reasonable. I would be more concerned with what label of abrasion / UV protection their labels offer.
For example, I don't think gear would make me these.
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