The ISO 186:2002 standard specifies a method for obtaining representative samples from large quantities of paper or Cardboard, including solid fiberboard and corrugated fiberboard, for testing to determine whether its average mass meets the set specifications. The standard applies to various types of paper and Cardboard, including newsprint, Encasement paper, Spreader paper, etc. It defines the sampling plan, sample size and collection method to ensure that the samples are representative and can accurately reflect the mass level of the whole batch of products. Through this standard, the production mass of paper and Cardboard can be effectively controlled, providing a scientific basis for international trade and mass assessment.