When you receive a quote for a CD duplication package, you’re going to notice these numbers describing the printed insert: 4/4, 4/1, or in some cases, 4/0.
These numbers refer to the color print on each side of your paper insert. When an insert is printed four over one (4/1), the four means full color and the one means black and white. A 4/1 insert is full color on one side with black and white printing on the other side.
Sales rep Zac Boyd explains this in more detail: