No. 2, or winter rats, are pretty well furred, but there are dark streaks and spots in the hide usually on the back.
No. 3 or fall are not full furred and the pelt is far from prime. The dark streaks show much more than later in the season.
No. 4, or kitts, are only partly grown or if larger are badly damaged.
Opossum is the only animal that may have a "prime" pelt but an "unprime" coat of fur. This makes opossum rather difficult to assort unless turned fur side out.
If opossum have been properly skinned and stretched they will, when unprime, show a dark blue spot on the under side at the throat. The plainer this spot the poorer the fur.
Good unprime skins are No. 2; poor unprime skins, No. 3; the very poor and stagey, no fur, are No. 4, generally known as trash and of no value.
The other fur-bearers, such as mink, otter, beaver, fox, wolves, lynx, wild cat, fisher, raccoon, bear, badger, civet cat, weasel, etc., are graded much the same that is, all skins to be No. 1 must be caught in season, when the fur is prime, at which time the "pelt" is healthy appearing — never blue or black — must be of average size, correctly skinned, handled and free of cuts or shot holes.
Skins may be unprime from several causes, viz: caught too early, improperly handled, under size, etc. Unprime skins are graded No. 2, 3 and 4 according to how inferior they are. The fairly well furred unprime skins are graded No. 2; the low furred unprime skins are thrown to No. 3; the poorly furred are thrown to No. 4, while low stagey skins go to trash.
Some skins altho prime are so small that they grade No. 3. This, however, is the exception rather than the rule. Usually if prime, the under size will only put the skin down one grade.