Note on the Use of the Term Cut-Off Scar

JSGT 1954 V38 T049

The continued use of the term cut-off scar is in my view somewhat unfortunate, for it may be implied by those not familiar with the suction process that the marks on the base of the bottle are solely formed from that portion of the glass contacted by the cut-off knife. As is fairly well known, this is not the case. In fact, the marks appear during the final blowing of the bottle, although their formation at this stage is governed largely by the chilling of the glass by the cut-off knife after the initial cutting has taken place and when it is performing its second function of supporting the glass in the blank mould. This latter function, which has nothing to do with the actual cut-off action, has a profound influence on the final blowing and on the marks which appear on the base of the bottle.

A. Dingwall (Senior)