Dov

One more option if the jars will never be opened and only viewed: paint the inside of the glass.

Pour in a little acrylic paint, swirl to coat, drain the excess and let it dry. From more than a metre away that is indistinguishable from a full jar, it costs almost nothing, it adds no weight, and it dries in an hour rather than overnight.

It fails on close inspection and if anything opens the lid, so it depends entirely on how the props are used.

There are three routes, and for your use case — short text, several times a day — the third is by far the best.

Feed the note through an ordinary printer. Stick the note onto a carrier sheet of normal paper, print with the note's position set in the document, and peel it off. This works and it is fiddly, and there is a real risk of the note detaching inside the printer, which is exactly the ending you predicted.

Buy printable sticky sheets. Full-size sheets with a repositionable adhesive backing, made for ordinary printers. You print several notes at once and cut them apart. Reliable, and it means preparing a sheet at a time rather than printing on demand.

Use a small thermal label printer. This is the answer. They are cheap, they take rolls of small labels including repositionable adhesive ones, they need no ink at all, and they print a short list in about two seconds from a phone or computer.