I brought this subject up in another thread. Shellac is a natural substance secreted from an insect, the best shellac is mixed fresh from flakes using alcohol. Shellac can always be re-dissolved with alcohol and it is not known to be a very durable finish, but it dries fast and is easy to use and can be completely non-toxic when dry. It is actually used to give gloss to food products. It was also one of the only choices back in the day as a finish.

Lacquer was designed as a synthetic shellac, it has a long shelf life and it dries fast and is more durable than shellac. Dye can be added to lacquer to make it any color.

Polyurethane is basically liquid plastic. It is very durable but takes longer to dry. I suppose it could be difficult to remove due to it's adhesion and flexibility.

I see no reason that shellac should be the product of choice for sealing bar tape, I think it's tradition more than anything. Lacquer should work just as well, if not better and dries fast. The ultimate finish should be polyurethane as it's the most UV, moisture resistant and flexible of the three finishes, it just takes longer to dry.

I haven't tested any of these finishes on bar tape but have used all of them extensively to finish furniture.