Most people may not consider the development of a promo CD with your own music on it as print, however it is. Think about it, the case you put it in has paper on it that needs to be printed, and the Cd itself can be printed on with an image, or an image can be printed on a sticker and mounted onto the CD.
So when you know someone who wants to become the next Rihanna, maybe all they have to do is record themselves on their computer, bring their ripped music to a printer and let it go from there.
There are a couple of different options with the case. You can do a Jewel case where there is printing on the front, on the spine, on the back and the inside front cover so you can get as much information on there as possible. Most people use the back to list their songs and put their copy write information. The front is the cover design and the name of the CD, the spine can have the information of the artist and the record name, and the inside can be used for lyrics, or an image, or something to grab potential buyers attention.
There is also an option to have a case where the image just goes on in the front and the back and you do not need the spine.
SO the next time one of your friends wants to release their own music, do the research and see where they can get their cd ripped and how much it costs, because for a starting, starving artist a big professional recording studio is not you only option!