Beginning violinists are often given fret markings, in the form of bright colored 1/8" wide tape. Check with a music store that rents student level instruments for the tape. A lot of household tapes may be hard to remove, or leave glue behind. Masking tape is designed to be removed easily, as long as it doesn't stay on too long. Over time, it becomes very hard to remove cleanly, and leaves glue behind. If you use masking tape, remove it every few days and put a fresh piece next time you play. Stay away from duct tape, cellophane tape, electrical tape friction tape, etc. You might try the plastic static clings people use to decorate windows. I never tried it, but it might stick well enough. There's no glue on it to cause trouble.
Paul
Paul