Huang-shou-shan is a stone mined from Mount Shou. It is not as lustrous nor as fine as t'ien-huang, and hence is less expensive. When the finer stones were the exclusive prerogative of noblemen, the common people would collect the huang-shou-shan stone.
Li Ch'i-mao, the owner of the seals featured in this Sinorama series, explains that he "started collecting from these beautiful, but cheaper huang-shou-shan stones. A valuable stone from Mount Shou will have expensive t'ien-huang in the center, kan-huang stone in the next layer, and farther out a layer of huang-shou-shan."
Li's first seal was a gift from an officer in his army unit who liked Li's paintings. When Li first developed his strong interest in seals, he had no money for collecting, so he window-shopped and talked to experts and learned about seals. As his income from painting increased, he began to buy seals for his collection.
One of his favorite purchases came when Li was on a trip to Japan to exhibit his paintings. In a shop Li spied out a small huang-shou-shan seal tucked in a corner, covered with dust. He pretended to be interested in other items, and finally bought the seal for an exceptionally cheap price. He still delights in telling of this purchase.
Seals, or more properly, signets can be classified according to how characters are carved on their faces. Signets with raised characters are called "crimson inscriptions," or yang inscriptions. Signets with sunken characters are called "white inscriptions," or yin inscriptions. In the Ch'in and Han dynasties two thousand years ago, most signets used yin inscriptions, that left a clear impression on the mud seals used on bamboo documents. In the later T'ang Dynasty, yang inscriptions were used on the newly-invented paper documents of that period.