I found this product over a year ago. It comes in yellow, green, pink, and white, on a dispenser similar to scotch tape. The paper feels like the same paper used for the original Post It notes, and works well with a Sharpie pen for labeling. The back of the paper is fully-covered by the adhesive (unlike Post-It notes, which have a strip of adhesive only along the top).
I can label anything, remove the label and reuse it. I do this frequently with food storage as I shift things around from one container to another. The labels don't roll up at the edges or fall off after a few months. I first used the tape when I was moving, because I was using a lot of plastic storage boxes, which I couldn't write on, and the tape (I bought neon green) was so much easier to use than masking tape.
3M has terrific products in their Post-It line, (including a Post-It glue stick, which I used to use for gluing appointment and business cards into my Day Runner), but this is my favorite product for around-the-house. (Not that it wouldn't have a million uses in an office, classroom or lab.) They also put thought into designing the dispenser: the tape tears easily and cleanly, and it isn't such brittle, cheap plastic that it cracks if you drop it. I have used Avery removable labels, but they come on sheets, which are cumbersome and can get bent, come only in white (as far as I know), and require finding a pair of scissors if you need a small label. The tape is far more convenient. – Joan Blindsight