In the U.S., Poster board, Cardstock and Cover Stock thickness is usually measured in points or mill. This measurement gives the thickness of the sheet in thousandths of an inch.
Example: a 10 pt. card is 0.010 inch or 0.254 mm thick ; a 12 pt. card is 0.012 inch or 0.3048 mm thick.
Most Royal Brites® Poster Board, except for the White Poster Board, is coated on both sides.
The thickness and weight are as follows:
12 pt. – 98 lb – 265g/m2
Poster board, Cardstock or Cover stock which has single-sided coating is called Coated One Side, (C1S) can differ from the double sided coated (C2S) as follows: