Why a Small Spill Can Distort a Cardboard Game Piece
Cardboard is a network of paper fibers with tiny spaces between them. When water touches a cut edge, it can travel into those spaces by capillary action—the same pull that draws liquid into a paper towel. The edge is especially vulnerable because the fibers are exposed there, rather than covered by the smoother printed faces.
As the fibers take up water, they swell unevenly. One side of a piece may expand more than another, making it curl; layers can also loosen or separate. The damage can begin before the piece looks thoroughly soaked, so blotting a spill quickly may limit how far it spreads, though it cannot reverse swelling that has already happened.
The Design Tradeoff
A coating can slow water from reaching the paper, but it adds a manufacturing step and changes how the surface feels. It also cannot necessarily seal every cut edge. That leaves cardboard game pieces light and easy to print, but vulnerable at the very places where water can enter fastest: their edges.
