We've been 3D printing in metal, gold, and even sugar for years now—so it seems only natural that we'd also be able to print in glow-in-the-dark plastic. This week, MakerBot announced a limited-edition run of PLA filament that glows in the dark, just in time for Halloween.

The filament is made with phosphorus dye, which means it's pretty much the same familiar material that's used to make sticky stars and glowsticks. Leaving it in the light for a few minutes charges up the phosphors in the material, which radiate visible light—eg, they "glow."

The really scary thing, unsurprisingly, is how much it costs: $130 per kilogram, as opposed to $48 for a normal color. [MakerBot]