Looked at an older Indian recurve in a pawn shop today. It had some cylinders that looked and felt a bit like cork mounted on the string for a Mediterranean release. They were clearly meant to fit the shooters fingers. What are these and why are they not commonly used? Seems like it would be quite a boon to ditch the glove or tab.
That sounds like a "no glove" they were soft rubber material and have probably crystalized.
They are fine for bow fishing but really slow your string down because of the weight of the rubber cylinders and become problematic when shooting any distance.
Mike
As Mike said, they add weight to the string. If you don't mind losing a couple feet per second they work great. Mostly you see them on kids bows so they don't have to mess with a glove or tab. I know several good bowhunters that use them exclusively; they detest using a glove or tab.
Looking at their trophy lists, I don't think most critters can tell how fast the arrow is traveling when the arrow passes through them.