I had no idea that this was a thing. The Cold Jet machine shoots tiny pellets of dry ice at 600 to 1200 feet per second to effectively strip clean any surface it hits. When the pellets hit a surface they rapidly cool it to -109 F which causes rapid “differential thermal expansion and contraction” to remove tough contaminates. They can strip hardened tar from a paving machine, or dial it down and scrub the ink from a business card without damaging the paper. Unlike a sand blaster, the dry ice blasting media vaporizes on contact leaving no waste stream, though I have to wonder where all the tar “goes” when they are cleaning that paving machine. Awesome idea and it looks like it works great.