Our friends at Filaco sent us a spool of their new High Impact Polystyrene (HIPS) filament for testing. Accordingly, we spent many hours at our lab checking it out.
The HIPS filament comes in only a pure white color, which actually isn't much of a problem; the objects printed in this spectacularly white material look incredibly beautiful, as you can see in these images.
The thermal characteristics of HIPS are very similar to ABS, meaning you can try it using your printer's ABS settings. It could be extruded at slightly lower temperatures, but there's one issue we observed with that, as we'll explain in a bit.
HIPS is very soft and is quite easy to print. We encountered no snags or snaps with this filament. It is easy to load and easy to re-spool, which we had to do with an improvised hand drill apparatus as the spool provided by Filaco didn't happen to fit on our BFB printer.
At ABS temperature settings, HIPS prints nicely, but it is somewhat soft and this can be observed in larger overhangs where sloppy drips and dangles appear. Don't do what we did here!
The solution, of course, is to lower the temperature, but we encountered a slight problem when printing at lower temperatures: our unheated, blue-tape covered print bed did not hold the HIPS as well. At ABS temperatures, the HIPS stuck perfectly to blue tape. At lower temperatures, it came loose several times. We'd recommend printing the base layer at a high ABS-like temperature and then dropping the temperature below ABS levels for subsequent layers. We expect no such problems would occur with a heated bed.
One other problem encountered: slight brownish discoloration if the temperature was too high or if the hot extruder lingered around a spot for too long. We saw this rarely; most prints typically emerged just fine.
If you'd like a material that prints beautifully, we'd recommend you try Filaco's HIPS - just be careful with the temperature settings.