This case consists of 2 parts; a hard plastic part and a soft part.
I printed the hard plastic part with white PLA and the "soft" part with Realflex
...さらに表示 filament, so seperate prints. I am currently testing the dual extruder options as well. I myself didn't have the need for a raft as my print went well, but I did use a Brim. I used pretty decent bed adhesion when doing so, if you are not doing this I recommend a raft.
Enjoy your case! As the ones on the market are quite dull :)