To make this I tied string around a bottle, soaked the string in lighter fluid, lit it on fire, and, after letting it burn for half a minute, plunged the bottle into ice water, which would crack the glass along a decently even line.
Here are some older sculptures from 2007. The first three images are from a final project done for an introductory sculpture class. The last two images are sculptures made entirely of hemp twine, wound up with a power drill.