The BCW 3x4 top loading thick card holders are designed to hold cards that are thicker than standard trading cards. Heres an easy way to gauge the thickness of a memorabilia card. A regular card is about 20-pts. thick. Thus, you can stack up regular cards next to the memorabilia card and do some easy math. That is, if your memorabilia card is about the thickness of 5 regular cards, then it would need a 100-pt. holder.