To skin an animal "open", rip the skin on the belly from the point of the lower jaw to the vent, down the back of the hind legs and on the inside of the front legs across the breast to the point of the brisket. Animals that are intended only as furs may have the feet cut off, but bears, mountain lions, wolves and wolverines should have the feet skinned out to the ends of the toes, leaving the claws attached to the skin. This increases their value for mounting or for rugs. The skin should be peeled from the body, using the knife whenever necessary.
In skinning the beaver, rip the skin from the point of the chin to the vent and around the base of the tail and cut off the feet, but do not rip the skin of the legs. Skin the animal perfectly clean using the knife everywhere, as it is almost impossible to flesh a beaver after skinning. Not a particle of flesh or fat should be allowed to remain on the skin.
After all burrs, lumps of mud and blood clots have been removed from the skin it is ready for fleshing. For fleshing all cased skins prepare a narrow tapering board of sufficient length to accommodate the longest skins and plane it perfectly smooth, rounding the edges slightly. Draw the skin over this board flesh side out and scrape all flesh and fat from it, using some blunt instrument, such as a square edged knife or a hatchet. Turn the skin occasionally and do not flesh on the edges of the board or you may score the skin; be careful not to damage it in any way. Always turn the fur side out before laying it down, so as to keep it perfectly clean.
Open skins, if they have not been skinned clean, are more readily fleshed after they are stretched.
A good supply of stretching boards of various sizes should be made in advance of the trapping season. Soft pine, poplar, basswood, or cedar boards are best, and old dry goods boxes make excellent stretching boards. They should be free of knots and should be planed smooth so that the furs may be removed easily after they are dry.
For mink the boards should be from 26 to 34 inches in length and from 3 1/2 to 4 1/2 inches wide at widest part, and about 1/2 inch narrower at the shoulders from which point it should taper gracefully to the head and end with a rounded point. For marten, the boards should be a trifle wider. For the average fox or fisher, the board should be 4 feet long, about 5 1/4 inches wide at the shoulder and 6 1/2 at the base. For the otter the board should be about 1/2 inch wider and a foot longer. The average lynx will require a board about 7 1/2 inches wide at the shoulder and 9 1/2 inches at the base, by about 5 feet in length. For large muskrats the board should be two feet long by 6 inches wide at the base, 3/4 inches narrower at the shoulder and with a flat iron shaped head, but more rounded at the nose. One should have several smaller sizes also. For skunk and opossum the boards should be about 6 inches wide at the shoulder and 7 1/4 inches at the base, 28 inches long.
These dimensions are for the average animals, but it should be remembered that the sizes vary greatly in the various parts of the country. In the case of the skunk and the mink especially, there is a great difference in size.