Abstract: A system for protecting cards may include, but is not limited to: a sleeve portion including: a first sleeve panel having a rectilinear perimeter; a second sleeve panel having a rectilinear perimeter; and a sleeve perimeter portion, wherein the sleeve perimeter portion is coupled to both the first sleeve panel and the second sleeve panel along at least a portion of at least three sides of the first sleeve panel and the second sleeve panel, respectively, and wherein the sleeve perimeter portion retains the first sleeve panel and the second sleeve panel in a spaced-apart configuration defining a sleeve slot between a fourth side of the first sleeve panel and the second sleeve panel, respectively; and a cap portion configured to be removably coupled to the sleeve portion so as to at least partially cover the sleeve slot.