I opted to print 1¾ pages folded with the ¾ on the unseen side, but, with clever graphics/text you could use the ¾ to artistic advantage on the outside face.
The reason for 1¾ was principally to get two inserts on one A4 sheet, I suspect the ¾ might be a slightly different in American sized paper.

Add a guillotine and careful folding.

Figuring the right way to put the paper in for the second print can be a puzzle but I solved it by buying a printer that will do it for me. And will print direct to the CD. CD/DVD printing I decided was the easiest way to get designs on the disk when you don't know that the user will leave the disk in sunlight and the stick-on labels will curl while inside the player!!! It happens. They will blame you. I buy "Full Face" printable CD/DVD 's.

Now consider the reverse side of the case, where the insert won't be taken out, and the spine can carry text. Sizes are different again. Beware.

I use Word Text Boxes to show the cut/fold lines. Borders in faint grey.