Wood with seals needs a very detailed and unified structure; Moderate hardness, easy to cut, not broken; Small shrinkage, no cracking and no deformation. The best materials are Boxwood, Pear and Boxwood, the best materials are Bai Shu, Loquat, Chimonanthus praecox, Coral, Cortex Phellodendri, Camellia oleifera and Ginkgo biloba, followed by Eucommia ulmoides and Alnus cremastogyne.