Grey board

Paperboard is a thick paper-based material. According to ISO standards, paperboard is a paper with a basis weight (grammage) above 224 g/m2, but there are exceptions.[1] Paperboard can be single- or multi-ply. Paperboard can be easily cut and formed, is lightweight, and because it is strong, is used in packaging.
Another end-use would be graphic printing, such as book and magazine covers or postcards. Sometimes it is referred to as cardboard, which is a generic, lay term used to refer to any heavy paper pulp–based board. Paperboard is also used in fine arts for creating sculptures .