the.com/cardstock

means A heavy, stiff paper—thicker than regular writing paper but thinner than true cardboard—used for things like postcards, greeting cards, and index cards.

from A straightforward compound of 'card' (from the material used for playing cards and other stiff paperboard, tracing back through French 'carte' to Latin 'charta,' meaning papyrus leaf or paper) and 'stock,' here meaning supply or material stuff, as in 'raw stock.' No hidden drama in this one — it's simply the stock used to make cards, named for exactly what it does.