O-Pee-Chee Card Company
O-Pee-Chee is a Canadian brand that has manufactured trading cards since the 1930s. In the 1960s, O-Pee-Chee began a relationship with Topps that continued for decades. Working in collaboration, the two companies sometimes produced sets that were identical, except for the location of printing and the paper stock. If a card that appears to be Topps states on the back that it was manufactured in Canada, it is an O-Pee-Chee.