Related to two types of sheetings: open cell material and closed cell material. They are graded according to hardness index. For type 1 sheeting a single hardness level is specified, but for type 2 sheeting a range. For sheeting up to approximately 100 mm the material indentation hardness index is specified. For type 2, mostly available in thicknesses much less than 50 mm, it is necessary to use a test piece consisting of a number of plies, therefore the product indentation hardness index is specified. An annex about organic materials staining.