Default (for items without special names, as below):
poor, inferior, decent, fine, perfect
Weapons:
crude, rough, decent, fine, masterwork
Arrows:
curved, rough, decent, fine, superior
Clothing:
crude, rough, decent, fine, masterwork
Containers:
leaky, rough, decent, fine, beautiful
Food:
awful, bland, decent, tasty, delicious
Fresh animal skin and Fur :
ragged, harsh, decent, fine, superior
(A "decent" quality item will not show its quality in the item name.) The highest grade is worth 1.5 the price of decent. Fine is worth 1.25, rough 0.5. The lowest grade is not accepted for trades.
Source: Sami at this topic http://z3.invisionfree.com/UrW_forum/index.php?showtopic=2877#entry22016005