Card stock is the paper or material used to produce trading cards — and it matters more than you might think. Stock varies in thickness, weight, and feel depending on the set and product tier.
Higher-end and premium products typically use thicker card stock, which gives cards a more substantial, impressive feel in hand. Standard products use thinner stock that's perfectly fine for everyday collecting but won't have that same premium heft.
The quality of card stock can impact a card's value and desirability. Collectors notice the difference between a card that feels flimsy and one that feels built to last. It's one of those details that separates good products from great ones.