How I Cut a Bottleneck Slide

I use a $3 glass cutter that's usually in the mirror section of the hardware store. Note that you're not actually "cutting" -- you're scoring a line where the glass will naturally want to break. It's important not to double-back or overlap your score line, the glass will want to break at both lines and often chip out.

For a clean score guide: on a level surface I take an existing slide of my preferred height and rest the tip of a sharpie on it. Leaving the sharpie stationary, I rotate the bottle against the marker.

I use the inside corner of my L-shaped desk to cradle the bottletop. Note where you begin the score, this is you'll want to meet at the end. Leaving the bottle cutter stationary against the glass with firm pressure, I rotate the bottle with my free hand.

Heat the score line with a candle, rotating it and warming it evenly. Sticking the bottleneck under cold water should pop it off. Be careful not to let the slide fall into the sink.