Was PG only for fancy or table glass? And would "fancy" have included jewelry, for instance?
I expect you have checked up on Sowerby's patents around 1890. In case you haven't, you'd probably find this unproductive.
#3286, 1 March 1890 was for "moulds for blowing and moulding jugs, gas globes and other hollow ware", and
#not known, 23 December 1890 was for "cutting by electricity".
None of the other nearby Sowerby patents looks promising.
This thread may well surprise some readers who thought of Sowerby as a pressed glass works. Not so. It is difficult to find any aspect of glass manufacturing that Sowerby did not get involved with at one time or another.
One of the worst injustices prevalent today is the praise heaped upon Dr Christopher Dresser for the "Clutha" studio glass he designed, made by James Couper & Sons of Glasgow. In fact it was almost straight plagiarism of Sowerby's studio art glass, lauched some three years earlier. Simon Cottle attempted to correct this in his book accompanying the 1986 Sowerby exhibition, but no-one seems to have taken much notice. Or, are there vested interests at work here in maintaining the high price of examples of Clutha glass?
Sorry Chris, I strayed into tub-thumping mode! I must keep to the subject.
Regards, Bernard C.