To print this I needed a brim. The idea of the pencil ring is to allow for easier writing with less effort or strain on the hand. Does it work well? l don't know -- let me know! An idea I had when thinking of things to design for the current challenge. Ring size does matter, this one is ring size 24 which happens to fit my thumb and index finger. While I haven't tried it yet -- placing rubber bands may stop the pencil from sliding if even less pressure from the fingers is needed.