Mineralogy
"Hardness" is determined by comparison with other minerals. In the Mohs scale, a standard set of minerals are numbered in order of increasing hardness from 1 (talc) to 10 (diamond). A harder mineral will scratch a softer, so an unknown mineral can be placed in this scale by which minerals it scratches and which scratch it. A few minerals such as calcite and kyanite have a hardness that depends significantly on direction. Hardness can also be measured on an absolute scale using a sclerometer; compared to the absolute scale, the Mohs scale is nonlinear.
Paper and ink testing
% of moisure content in the paper is known as relative moisure content.High moisure content will increase the weight of the paper and increase the cost of paper. At the same time low moisure content will make the paper brittle and increases the chances of break in production.Roughness indicates varying degree of porosity of the paper. Porosity is a direct indication of paper to accept ink or water.