We use the styrofoam square method mentioned by Andi Grantham, but you can also use the little cork self stick pads used to protect inside corners of cupboard doors. Any hardware store has these in different sizes. It is best to stick these on when the knife holder it warm, and clean plus you can build these up to a preferred height. The styrofoam square is certainly cheap, and we simply use Scotch self stick tape on back so it can be moved to a place comfortable per operator. Leica Microsystems had addressed this problem with a nice hand/finger rest, removable if not desired, on their new 1950(?) cryostat knifeholder. It was quite comfortable, and I now hope they will retrofit their 1850 knife holder with a similar device for the brush method cryotomy afficianados (sp?)
To protect hands from cold and dishpan hand "perspiration", we also buy silk glove liners from a company called Winter Silks. These are thin, right/left handed, come in black or white, different sizes, and seconds are cheaper. There is no loss of dexterity when you put a latex or nitrile glove over these. We wash them with hand soap after using. Gloves that are stretchy or elasticized tend to cut the circulation in hands and fingers, and put pressure on painful joints, but the silk gloves do not have any spandex in them. Winter Silks has a website.
Histonet mailing list