We have started to add HIPS to our offerings, starting with 8 colors. We have 3 mm in natural/translucent as well. In time, we will expand our color selection, and also match the selection for 3mm users.
http://toybuilderlabs.com/hips-175
Is the HIPS filament rigid once printed? Or is it flexible?
It is similar to ABS in rigidity and printing temperature.
@Joseph_Chiu , what about curling, build surfaces to print on, etc?
It is similar to ABS in my experience - it is similarly prone to shrinking and prints on the same surfaces with similar results. I print on kapton most of the time, and it works quite similarly.