The types and brands of gypsum powder sold on the market are different, and the quality of gypsum powder varies from good to bad. So choosing suitable and good gypsum powder can achieve the most perfect effect.

　　在选用的时候，不妨观察石膏粉的颜色。主要分为灰色，黄色，白色。灰色的石膏粉大都为建筑用石膏，仔细观察或浸水后便能发现其中的黑色小颗粒杂质。该类石膏脆，但便宜。日常用于墙面的装修，在建材市场能买到。

　　When choosing gypsum powder, you might as well observe the color of gypsum powder. It is mainly divided into gray, yellow and white. Grey gypsum powder is mostly used for building gypsum. After careful observation or immersion, small black impurities can be found. This kind of gypsum is crisp but cheap. Daily wall decoration, in the building materials market can be bought.

　　黄色的则为黄石膏粉。一般可以用来制模，雕塑。好的黄色石膏粉坚硬，细目也很符合美术制作的要求。

　　The yellow one is yellow gypsum powder. Usually it can be used to make moulds and sculptures. Good yellow gypsum powder is hard and detailed, which also meets the requirements of art production.

　　白色石膏粉是我们为广见的石膏材料，广泛用于装修、制模、雕塑等多类领域。好的白色石膏粉细目高，硬度好。有的还添加了少许碳酸钙，达到了极为坚硬的效果。

　　White gypsum powder is our most common gypsum material, widely used in decoration, moulding, sculpture and other fields. Good white gypsum powder has high fineness and good hardness. Some also added a little calcium carbonate, to achieve a very hard effect.

　　选购石膏时，包装上的各类数据可能使我们不知所择，因此不妨来了解一下有关石膏的各类数据。

　　When choosing gypsum, we may not know what to choose from the various data on the package, so we might as well learn about the various data on gypsum.

　　1，细目（细度）：顾名思义，细目代表着石膏粉的细腻程度，特硬白石膏的细目通常为1100目上下，建筑用石膏的细目约在300目左右，由此我们便能看出许多差距。

　　1. Details (fineness): As the name implies, details represent the fineness of gypsum powder. The details of extra-hard white gypsum are usually about 1100 meshes. The details of building gypsum are about 300 meshes, so we can see many gaps.

　　2，抗压强度：抗压强度指的是外界把石膏压碎裂的力的大小，美术用白石膏的3小时抗压强度为8.1毫帕，建筑用石膏的3小时抗压强度约为4.9毫帕。

　　2. Compressive strength: Compressive strength refers to the external crushing force of gypsum. The three-hour compressive strength of white gypsum for art is 8.1 millipa, and that of gypsum for construction is about 4.9 millipa.

　　3，抗折强度：抗折强度代表单位面积使材料承受弯矩断裂的力的大小。美术用石膏的烘干抗折强度约为10~12毫帕，建筑用石膏则为8.4毫帕左右。

　　3. Flexural strength: Flexural strength represents the amount of force per unit area that causes the material to withstand moment fracture. The drying flexural strength of gypsum for art is about 10-12 MPa, while that of gypsum for construction is about 8.4 MPa.

　　4，粘结强度：说道粘结强度，举一个例子或许能更易理解——分别向面粉与沙子中加水并搅拌，面粉能粘成一团，而沙子一触即散。美术石膏的粘结强度因种类不同（分为粘结型和普通）因而其强度也会有所差异，建筑石膏也是如此，因而购买时好咨询店家。

　　4. Bond Strength: When it comes to bond strength, it may be easier to understand, for example, by adding water to flour and sand and stirring them separately, the flour will stick together and the sand will disperse when touched. The bond strength of artistic gypsum varies according to its type (divided into bond type and common), so does the strength of architectural gypsum, so it is best to consult the shop when purchasing.