In general terms, the press and blow process is used for jars and the blow and blow process for bottles. An alternative, for lightweight bottles, is the narrow neck press and blow process. The press and blow process is generally best suited to produce jars with a neck finish size ≥35 mm (≥1.25");the other two proceses are more suited to produce bottles with a neck finish size of ≤35mm (≤1.25") (Fig 6.4)
The narrow neck press and blow process offers better control of the glass distribution than the blow and blow process, allowing weight saving in the region of 30% to be made (Fig. 6.4)