2). Principles for selecting raw materials for food engraving. When selecting raw materials for food engraving instruments, just pay attention to the following principles. 1. The selection should be based on the theme of the sculpture, and must not be blind. 2. Choose raw materials according to the season, because vegetable raw materials are very seasonal. 3. The selected raw materials, especially the solid parts, must be seamless, with neat and fine fibers, heavy weight and pure color. Because food carving works only have a smooth surface and texture, so that people can feel its beauty. 3). Storage of raw materials, finished products and semi-finished products for food engraving. The raw materials and finished products of food engraving are subject to their own texture and extreme limitations. They are easily deteriorated if not properly stored. It is a waste of raw materials and time, which is a pity. In order to extend their storage and use time as much as possible, here are several storage methods. 1. Preservation of raw materials: Fruit and melon raw materials are mostly produced in summer and autumn when the climate is hot. Therefore, it is advisable to store the raw materials in a cool and humid place to keep the water from evaporating. Radishes are produced in autumn and used in winter. They should be stored in underground kilns and covered with a layer of sandy soil more than 0.3 meters thick to maintain moisture and prevent freezing. They can be stored until spring. 2. Preservation of semi-finished products: The method of preservation is to cover the engraved semi-finished products with wet cloth or plastic