In order to show the antiquity of trees, sometimes a chisel or a sharp carving knife can be used to carve the trunk according to the modelling technique, so as to form a natural concave-convex change, and part of the bark can be stripped off, and even half of the trunk can be split (for example, plum piles can be split to dry the shape), so that the trees present a natural withered and old posture. But when carving, you must not show traces of artificial knives and axes. This method is mostly used for larger conifers and old stumps.