For it, you'll need access to a laser cutter.
Step 1: Gather Your Materials!
In this case, I'm using some really beautiful, semi-glass, very heavy paper (this is typical for what would be used to bind paperback books with a white cover.):
I love calipers, and used them to find that this paper is 0.83mm (probably closer to 1.0mm) thick.
(I love this paper)
Step 2: Planning Some Sizes
I know that a CD is ~120mm wide (thanks again, caliper!).
I think I'd like around 2cm of "padding" from the edge of the case to the edge of the cd, which means that my final case should be around 160mm wide.
I also need a "spine" (the area where the the case folds). This should be about 1/2cm.
The total, final size for the piece I'm going to cut is: 160mm (front) + 160mm (back) + 5mm (spine) = 325mm wide x 160mm tall.
TO THE INKSCAPE!
Step 3: Design Your File in Inkscape
This is clearly inferior to a dedicated CAD software [if you have access to one; I don't]
Here I have created a 325x160mm box, and started laying out what my final project will look like. The solid lines here are things that the laser will transit. The dotted lines are things that are just for me to look at.
Green, in this case, will be used to score the paper (to make it easier to fold), but won't actually cut anything.
Download the linked PDF for a template you can use to make your own!
Step 4: Add Your Tracks, and a Personal Message
NOW! An important bit! To get the laser to just cut the edges of the letters, what I have done is selected my text, brought up the fill and stroke dialog (ctrl+shift+f), disabled the objects' fill, and added a stroke to them.
This places a line just on the exterior of the letters, which is what we want.
In the template, there are two boxes. One is the "interior" sheet of paper, one is the "exterior" piece. They will be glued together at the end.
Export this file to a PDF (inkscape's DXF exporter doesn't seem to work properly), and take the file to your laser cutter!
(You have a big laser cutter, right?)
Step 5: Load the File Into Your Laser Cutter
Load the files into the laser, and cut them.
Step 6: Now You've Got Your Pieces! Lasering Done!
Pre-fold them along the scored creases.
I wore gloves during this to keep the paper as clean as possible
Step 7: Apply Glue!
(In this picture, I actually folded one of these pieces of paper the wrong way. OOPS! Pay attention to where you're gluing!
Step 8: Let It Dry
Step 9: All Done!
(Do not stencil onto things you do not own!)
I'm really happy with how this came out. It easily looks like something that you'd find commercially.