It is a single-layer gray board of 1300 gsm. The STONE brand is made from recycled paper and corrugated paper. It can be used for packaging, stationery, etc. However, the grammage range of Grade B is only 750g to 1500g.
Exercise Book use Single Layer Board Sheets 1300gsm Grey Board
Grade B grey board
12% with ±2.5%
Sheet: standard seaworthy packing.