non-adhesive jar/bottle labels?

I use Weck jars

I have no experience with canning, but you could order wider rubber bands and write labels in pen on those and slip them over the jar. The bonus is that if you place it at the widest point on the jar it will reduce clinking/breakage during storage. And they would be reusable!

Staples carries 1/4 pound of these 1/2" wide rubber bands for $2. (Anybody know why they measure rubber bands by weight?)

How about one of those pencils made to write on photographs?

Yes, that's precisely what I meant: I couldn't think of the name off the cuff. Old age isn't pretty....

How about using a water-soluable pen (like an overhead pen) and a static cling label like the ones they use for oil-change reminders? They stick reliably in a pretty harsh environment (sun + hot) for 6+months and yet remove easily.

I'd write with the overhead pen, then cover it with the label to keep from smearing.

Office depot seems to sell inkjet-printable ones. I would worry that this would make the ink permanent rather than reusable, but maybe that is only on one surface or you could remove the ink-capturing coating (assuming it's a coating).

You could just print on the labels and reuse, if you can a specific set of items.

KISS-Just use a sharpie, it is a good compromise which is what you are asking for.

We use day dots similar to these at my job. They are nice and adhesive, but also water-soluble, so they just magically go away in the dishwasher. These are the 1"x2" ones, but they have different sizes, and can be found online or in food service supply catalogs for cheaper.

https://www.daydots.com/article.asp?HKEY=002&strPRODH=001001009&strMATNR=11009-00-00&page=1

I use freezer tape. I find it is easy to remove because it doesn't tear like a label would. To make it even easier to remove just fold one end of the tape into a tab. It is adhesive, but it not difficult to remove which seems to be the primary intent of the question.

I would suggest grease pencil (aka china marker). It makes a waxy mark that won't go away if it just gets wet, but it can be removed with by rubbing with a paper towel and/or using a solvent after the mark has been on the glass for a long time.

sharpie can be removed with either acetone or alcohol (so use nailpolish remover or vodka)

Sharpie (permanent magic markers that write on glass) can be removed with acetone or ethanol so you write on the jar and remove with a cloth wet with nailpolish remover or vodka.

Sharpie on Gaff Tape. Removes easily and leaves no residue behind.

You said non-adhesive, but Post-It tape works well for me. It comes in a variety of widths, colors, and adhesive (super-sticky or regular.) Regardless of the type of adhesive, the tape peels off easily and cleanly. I have tried china markers and sharpies, but the markings are hard to read on clear glass without excellent lighting. In a cabinet with all the bottles and jars turned in various directions, the tape is far easier to read.