yeah given the link I supplied was to phone cases on thingiverse - not sure he actually clicked the link :-)

get yourself some ploymakr polyflex flexible pla.
Prints are hassle free, super tough (we printed a single layer the other day and couldn't tear it) rigid enough to print fine detail and really flexible.

globasfsd do 10 metre samples - should be enough to print a couple of cases, at least.