Thumb Guard Wood Carving Tools - Lylence Thumb Protector,Whittling Thumb Guard, Leather Finger Protector, Thumb Guard Wood Carving, Carving Thumb Guard

Get a thumb guard/protector. Common for woodcarving and opening sea shells. Random one from Amazon This one is made from leather, you can get metal mesh, silicone, but you said those are not preferable options for you