The circle is 1 and other products; Square is second-class; Triangles are third-class; Unqualified products are printed with the words "defective products".

2. Enamel: (1) Qin enamel, with leather compound as the raw material of surface glaze, and the trademark is blue or light blue. (2) Antimony enamel, with antimony oxide as the raw material of surface glaze, is easy to precipitate when it meets acidic substances, which is harmful to human health. Its trademark is sky blue.

3. Cloth: Small color labels are hung on the cloth. Red indicates products such as 1; Green represents second-class products; Blue stands for third class; Black means unqualified.

4. Wool: In addition to the trademark and place of origin, three numbers are printed on the sign. 1 stands for raw materials. 1- domestic pure wool; 2- Imported pure wool; 3. Blending imported wool with viscose fiber; 4- new products; 5— Domestic wool mixed with felt fiber. The last two numbers indicate the thickness and number of branches.