Today I approached the stall of one of my regular suppliers, a lady with a good eye for interesting glass, and saw from some distance an obvious example of Whitefriars Knobbly, a chunky medium sized example with the bulbous base, in a good green with a thick casing of clear crystal, similar in shape and size to Jackson plate 154 (iv).
On closer inspection I immediately realised that it was not Whitefriars at all. The indentations are quite different, trailing away at their lower edges, and with a protruding egg-shape at the bottom of each. The pontil was finished with an applied blob of crystal, stamped with the trademark "LG" or "LC" with the letters combined, in the same way as the leaping salmon of Strathearn, the combined IOW / flame of Isle of Wight Glass, and the lions / leopards heraldic shield of Guernsey Glass. The outcome is an attractive high quality production that left me somewhat mystified as to how it was made.
The return of the "G" forms the horizontal stroke of the "L", with the tall vertical stroke intersecting the top of the "G" (or "C").
I have checking Haanstra, Jackson II, and Benson with no luck. The most obvious possibility is a recent mark of Leerdam Glass, not yet in the reference books, and well known for combining letters to form a logo or trademark.
Anyone ideas of maker, designer, dates and any other information about this attractive art glass?
And, Nigel, note that I restrained myself from using the now famous Bensonic appellation, despite being sorely tempted.