[2] A wide variety of protective devices have been developed following the introduction of collectible card games, including the bulky "top-loader", a rigid plastic case with one open end (essentially a box for a single card) and the less-expensive simple "card sleeve", a card-sized envelope of clear plastic, with one end open.
Once collectible card games became popular after the advent of Magic: The Gathering, new technology was needed for two reasons.
Despite other companies like KMC and Player's Choice bringing this issue under control, it is still a common problem with many card sleeve manufacturers.
The increasing popularity of card games has resulted in the entry of competitors in the protective sleeve market, including companies such as Players' Choice, Dragon Shield, and Armor Shield.
These card sleeves are now offered in six sizes and two thicknesses for over 500 board games.