And there lies the trap: 3D printing technology has developed away from FDM printing and towards SLA printing, because the results of SLA are better. But FDM printing with PLA is essentially harmless, and is something you can do without many safety precautions; a simple HEPA filter on the printer, and not touching the hot nozzle is enough. SLA printing is significantly more dangerous, as it involves handling a rather toxic acrylic resin liquid; you will want to have very good ventilation, preferably a fume hood, and you need to wear gloves. You will also need to handle the flammable isopropanol used for washing, although most of us have gotten quite used to handling that, given that it is the main component of most hand sanitizers. I really, really wouldn't recommend a SLA printer for kids. And personally, although I am trained to handle chemical substances safely, I don't use a SLA printer in my home, because of safety concerns.

In other words, a SLA printer is not really a mass-market consumer product. 3D printing technology has evolved *away* from consumer-friendliness. Which in part explains why earlier forecasts of a 3D printer in every home have not come true. The other half of the problem is that even with a SLA printer it is extremely difficult to use a 3D printer to replace some broken plastic piece in your household. The emblematic model of FDM printing, the hairy lion, sure looks cool, but has no practical use. 3D printing is a rather complicated and expensive way to produce cheap plastic objects and toys. Still, I believe that a technology development towards more user-friendly and easier to use FDM printers would have led to a wider spread of the technology than going down the high-quality SLA route.