Q: What's a Cassingle? A Cassingle is a cassette tape packaged only in a paper sleeve called an O Card, which is printed flat then glued on one side to create a box Audio Cassette Tape Stars and Stripes O Card Cassette Sleeves 20+ years of friendship and counting also, I just learned today that this particalur kind of cassette sleeve was called a J card? What??, ., ., ., Mix tape cassette playlist friendship goals Amazon.com: 10PCS Clear Dust Proof Resealable Protective Outer PET Display Sleeves for Cassette Tape : Electronics Cassette Credit Card Holder Mr. Scarface : Now I Feel Ya (Cassette Tape Card Sleeve Rap A Lot) *Rare* *VG*