Old ink stick
Eastern painters and calligraphers used to store ink sticks. The reason to do so is to giving the glue in the ink stick the time to cure - the longer it is stored, the better the quality it will be. The ink ground from a new stick is gluey and tends to produce uneven tonal work on silk or rice paper support, while that from an old one, in which the stickiness of the glue is reduced by the cure, produces even graduation of shade.
This custom eventually turned into a hobby, making ink sticks a collectable craft. To feed collector's taste, all major ink shops strove for exquisite designs, especially since the 17th century when Chinese ink-making reached its perfection. These fancy inksticks were expensive, 20 tael fine silver for half kilogram in comparison with 1.5 tael in ordinary one. However, they were greatly appreciated by both collectors and consumers. Today's antique ink sticks are mostly from this period. The older ones are rare.
The aging of an ink stick can be told by wrinkles on its body. The longer it has been stored, the rougher the texture appears. The tips below is how an antique is judged.