First, actual tare weight. That is, the actual weight of packages of the whole commodities. Second, average weight. In the case of uniform packaging, a certain number of packages can be extracted from all the goods to be weighed, the average weight of each package. Third, get used to tare. Suitable for standardized packaging, the weight of the package is known to all and there is no need to weigh it. And the last one, agreed tare weights. The packing weight agreed by both parties.