The future of manufacturing is distributed [video]
FR4 is an electrical-grade, dielectric fiberglass laminate epoxy resin system combined with a glass fabric substrate. The difference between G10 and FR4 is that FR4 is a fire-retardant grade of G10 and it can be safely substituted when G10 is called out. It has extremely high mechanical strength, good dielectric loss properties, and good electric strength properties, both wet and dry.
Aleksandra Mechanical Engineer at 3D Hubs