Why do mtg foils curl

Overview

Magic: The Gathering foil cards, first introduced in 1997 with the Urza's Legacy expansion, have experienced curling issues that became particularly noticeable around 2015. The problem escalated significantly with the 2016 Kaladesh set, when Wizards of the Coast changed their printing process and materials. By 2017, the company publicly acknowledged the curling problem in official communications, noting that it affected cards worldwide. The issue became so widespread that it sparked numerous community discussions, with players reporting that 80-90% of their foil cards developed noticeable curling within weeks of opening packs. This problem has persisted through subsequent sets, though Wizards has attempted various manufacturing adjustments to mitigate it, with mixed results. The curling phenomenon has affected both competitive play and collector markets, with curled cards sometimes being considered marked in tournament settings.

How It Works

The curling mechanism involves the different physical properties of the cardboard backing and the plastic foil layer. When humidity increases above 60% relative humidity (RH), the cardboard layer absorbs moisture and expands, while the plastic foil layer remains relatively stable. This creates a bending moment that causes the card to curl with the foil side becoming convex. Conversely, when humidity drops below 40% RH, the cardboard contracts while the plastic remains stable, causing the card to curl in the opposite direction with the foil side becoming concave. The process typically occurs within 24-48 hours of exposure to humidity changes. The degree of curling depends on several factors including the specific card stock used (which changed around 2015), the thickness and composition of the foil layer, and the rate of humidity change. Modern foil cards use a thinner foil layer applied to the cardboard, which exacerbates the differential expansion problem compared to earlier printing methods.

Why It Matters

Foil curling has significant practical implications for Magic: The Gathering players and collectors. In tournament settings, curled cards can be considered marked cards, potentially leading to game losses or disqualifications under tournament rules. This has forced competitive players to avoid using foil cards or to implement complex storage solutions. For collectors, curling reduces card value and preservation quality, with severely curled cards sometimes losing 30-50% of their market value. The issue has also impacted the secondary market, where sellers must disclose curling conditions. Beyond financial concerns, the problem affects gameplay experience, as curled cards don't shuffle or handle as well as flat cards. Wizards of the Coast has faced ongoing criticism for the issue, which has persisted despite multiple manufacturing adjustments over the years.