You can print a mold with your 3d printer and then use silicone rubber to build your very custom USB flash drive case…
Can u plz tell me more about 3D printing? How it works? how much it costs? In India its still in its very initial phase.
@Vibhooti_Chauhan 3d printing is a big topic, and it’s still young and evolving. I built a 3d printer by myself using sparse instructions you can find all over the web. Just take a look to reprap project http://reprap.org/wiki/RepRap_Options
Thnx @Andrea_Fontana
It is corn starch, used to prepare rubber mixing it with silicone. Search for “oogoo”.
Cool project! 
Are you going to document the process? Would be great for other makers like me.
@enhydra it’s not a secret: just search “oogoo”. It’s a mix of corn starch and silicone that I pressed with fingers inside the mold you see in photo
Love it!
@yaron_atia I used oogoo recipe: 50% silicone and 50% corn starch. What’s your recipe?
I use molds silicone , two components are mixed together and after two hours its Harden