Wash the bottles thoroughly, soaking them in hot water to remove the labels, and leave them to dry, Practice using the bottle cutter on plain glass bottles before using ones you may want to keep or decorate further
Arrange the bottle glass cutter on the bottle with the washer in the neck of the bottle and the cutting edge at the point where you want to cut. Revolve the bottle glass cutter to score a cut in one even stroke. Don’t overlap the scoring.
Pour 1 liter / 1¾ pt of boiling water and a cup of cold water into a heatproof jug. Stand the scored bottle in a plastic bowl. Place a funnel in the bottle and use it to pour the hot water in to fill the bottle.
Immediately run an ice cube all around the score line on the outside of the bottle. The bottle will start to crack. Carefully lift the top piece away.
STOP! Keep the ice moving – if you hold it in one place for any length of time, the glass may start to crack at an angle to the scored line.
Set the cut edge of the glass on a sheet of wet and dry sandpaper. Rotate the bottle, moving it backwards and forwards, to smooth the edge and to remove any small chips of glass.
Run the bottle under cold water instead of applying the ice cube to the scored line