The GB/T 6739-2006 standard applies to the determination of pencil Hardness for Paints, varnishes and related products. The standard describes a method for evaluating the scratch resistance performance of paint films by pressing with a series of pencils with different Hardness on the surface of the paint film. The test can be used for the uppermost coatings of single coatings or multi-coating systems and is a fast, cost-effective method for comparing the Hardness of different coatings. The standard specifies in detail the test conditions required for the assessment of pencil Hardness, the type of pencil and the method of use, ensuring the accuracy and repeatability of the measurement results. In addition, the standard also covers the preparation of the sample before the test, the test operation procedure, the precision requirements for the determination of the results, and the content and format requirements of the test report. The implementation of GB/T 6739-2006 helps to evaluate coating Hardness and provides an important quality control tool for the Coatings and Coatings industry.