Mathematicians use the sign ∞ to express infinity, which is derived from the Latin infinitas, which means "no boundary". In 1858, the German mathematician Mobius discovered that the paper tape loop made by twisting a piece of paper 180° and then bonding the two ends together has magical properties. The two-dimensional one-sided curved surface existing in the three-dimensional world is the famous Mobius ring. Mobius ring is not only a classical model carrying the concept of infinity, but also looks like the symbol of infinity. The Mobius ring is drawn on the back of the card in a minimalist way, twisting, rotating, reciprocating, cycling, interleaving, endless and infinite. Design details hide the designer's thinking and pursuit of time, space and cardistry effect.