The glasses were perfect on arrival and thin at the edges by spring. That timeline points at the wash, and specifically at which ink was used.

What organic ink actually is

Epoxy and UV-cure inks are printed and then cured at low temperature.

The result is a durable film sitting on the surface of the glass, not part of it.

What a commercial wash does to it

High-alkalinity detergent attacks the binder while heat and jets abrade the film.

Several cycles a day compounds fast, which is why the failure looks sudden.

What firing changes

Ceramic frit is fired in a lehr and fuses into the glass surface as glass.

There is no film left to attack, so the decoration outlives the glass.

When organic ink is still the right answer

Retail and gifting glasses that go home in a box and see a domestic dishwasher.

It costs less and reaches brighter colours. Buy it knowing what it is for.