More than a pound number
Cardstock is sold in several weights and finishes. A US label may use cover or index basis weight, while other labels give GSM. Keep the grade name with a pound number: 80 lb cover and 80 lb text use different basic sheet sizes.
There is no single GSM at which every manufacturer starts calling paper cardstock. Weight also does not uniquely determine thickness or stiffness.
Printing templates
Check your printer’s supported paper weight, thickness and feed instructions. Use a manual or specialty-media feed only as its manual directs. For measured templates, choose Actual size and check a printed measurement before using the sheet.