|Suggested Tools:||glass cutter, laser cutter, diamond bits|
|Similar (More or Less):||acrylic glass, (some) casting resins|
Glass is tricky to work with as it tends to shatter upon the slightest mistreatment - make sure to wear adequate protection!
A laser cutter is also potentially able to score a break line (please let us know if you've tried it!)
Most methods you find use heat stress to break the glass: either a burning string (reportedly not very good quality), a glowing wire (build article in c't Make: 6/17) or baths of water after the bottle has been scored with a glass cutter the old-fashioned way.
Lukas would like to try out this cutting jig or the electric one from c't Make:, who else is interested? We could also host events using and/or making these jigs with people interested in re-using their glass waste! Another option could be a 3D printed collar like this one which should work better on irregularly shaped bottles than a fixed jig would.
A laser cutter and diamond rotary tool bits are suitable for engravings.