Glass

There are currently no know RepRap printers which print glass, however there are some 3D printers which can print glass including:

• G3DP2: https://www.3dnatives.com/en/researchers-mit-3d-print-glass-290120194/
• Bastian Rapp's team at Karlsruhe Institute of Technology: https://www.smithsonianmag.com/innovation/you-can-now-3d-print-glass-180962951
• Amos Dudley, glass casting from 3d printed moulds https://hackaday.com/2019/08/08/3d-printing-glass/
• Markus Kayser's solar powered glass printer using sand: https://hackaday.com/2011/06/25/selective-solar-sintering-with-sand/