Another Flexible Filament

Looks good actually

 

I haven't tried the FlexPLA. The material I use is slightly more flexible and slightly more expensive than regular PLA, but not nearly an elastomer.

I do want to toss out a small caution on the ninjaflex (not a recommendation against it mind you) from prior experience in industry. The material (polyurethane) is a sensitizer when melted. If you're not normally bothered by polymer fumes and you start using it without proper ventilation, you might start to have a reaction and then start having reactions to other polymer fumes that didn't bother you previously. This is one of those things that affects a small percentage of people.