Most hobbyists do their 3D printing with either PLA or ABS material. Those are affordable, versatile, and generally yield nice results. Other less common filament materials include PETG, nylon, TPU, and various kinds of wood or metal fill mixtures. All of those are continually being refined, but it’s rare that we see a completely new type of filament. That’s what makes ColorFabb’s new LW (Light Weight) filament series so newsworthy. These unique filament materials expand into foam when they’re printed, and the YouTube channel CNC Kitchen recently put them to the test.

ColorFabb has released two new filament types in this new series: LW-PLA and LW-TPU. As the names suggests, these are modified types of PLA and TPU. But the changes are pretty significant. The materials have been embedded with a special agent that causes gas expansion when the filament is heated inside of a 3D printer's hot end. The gas expansion causes the material to foam up with tiny pockets of gas while you’re printing, resulting in a foam part. Importantly, the density of that foam is directly proportional to the temperature of your hot end. Printing at a low temperature results in a high-density foam, while printing a high temperature produces a low-density foam.

The question, of course, is how well the material performs and what you can do with it. CNC Kitchen printed the LW-PLA with many different settings in order to test it. As expected, the parts lose strength as the density decreases. But that might be acceptable for many applications. You can even vary the density within a single part, which is very useful for parts like plane wings. As explained in the video, it can be tricky to tune the settings properly, because the flow rate and temperature go hand in hand. If you’re looking for an interesting new material to check out, be sure to watch CNC Kitchen’s video to see if the ColorFabb LW filaments are for you.