Crosshatch Adhesion Test. Test per GMW14829, Method A. Coatings must perform both as-received and after humidity exposure to GMW14729 of the hours shown in Appendix A, Table A1. Requirement: Rating 0 or 1.Testing to High-humidity Environments. Expose samples to humidity per GMW14729, Method A or B.Coatings must withstand humidity exposure to the hours shown in Appendix A, Table A1. Requirement: No surface change.