So far so good. But they need a little time to get to you. I etched acrylic with my mpcnc. They do an excellent job of removing waste so it doesn't build up in the melt. Although I'm using a 30,000 rpm router. Outstanding quality for the price. Update I was able to carve some acrylic night lights with these pieces and they worked great. Here are some photos. Everything is done with the same nozzle so that the acrylic does not stick together when cutting.