The types and brands of gypsum powder sold on the market are different, and the quality is also mixed. Therefore, the selection of appropriate, good gypsum powder to achieve the perfect effect of production.

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, might as well observe the color of gypsum powder. It is mainly divided into gray, yellow and white. Most of the gray gypsum powder is used for construction. After careful observation or immersion in water, we can find the small black particles in it. This kind of gypsum is brittle but cheap. Daily use for wall decoration, can be bought in the building materials market.

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 Huangshi powder. It can be used to make molds and sculptures. The fine yellow gypsum powder is hard, and the details meet the requirements of art production.

白色石膏粉是我们更为广见的石膏材料，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 the most widely seen gypsum material, widely used in decoration, mold making, 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, the various data on the package may make us do not know what to choose, so we may as well learn about the various data about 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, the details represent the fineness of gypsum powder. The details of extra hard white gypsum are usually 1100 mesh, and the construction gypsum is about 300 mesh. From this, 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: the compressive strength refers to the external force to crush and crack the gypsum. The 3-hour compressive strength of white gypsum for art is 8.1 MPa, and that for building gypsum is 4.9 MPa.

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: the flexural strength represents the force per unit area that makes the material withstand bending moment fracture. The drying bending strength of gypsum for fine arts is about 10 ~ 12 MPa, while that 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，因而购买时更好咨询店家。

4. Bond strength: when it comes to bond strength, it may be easier to understand with an example - add water to flour and sand separately and mix them. The flour will stick together and the sand will disperse when touched. The bond strength of art gypsum is different due to different types (divided into bonding type and ordinary type), so the strength of construction gypsum is also different. Therefore, it is better to consult the store owner when purchasing.