Paper is defined by four basic parametres that are useful to understand to an elementary extent when we are choosing the most suitable printing medium.
Paper whiteness is indicated in whiteness percentage that indicates the amount of Magnesium Oxide (MgO). To define whiteness, standards ISO or CIE are used. Paper whiteness affects the quality of the print and its contrast.
Property of paper to prevent light rays from passing through. It is indicated in percentage of intercepted light. Opaque paper hast the opacity of 100%. Higher opacity is required mostly for colour duplex printing, so that the graphics won't show through to the other side.
Paper Weight (Grammage)
Paper density is its mass per unit volume. It is indicated in grams per cubic meter (g/m²).
Spatial quantity of paper cross-section in relation to specific square weight. Paper thickness has a direct effect on paper firmness and it especially affects functionality of the paper in regular printers.