Rob Parsons challenged me about my reticence to identify the Golden Guinea as a product of the house of Mentmore. Really, I have no difficulty in saying it’s a Mentmore pen but so far as I know, no invoice or advert has turned up making the attribution incontrovertible.

Styles of machining and methods of assembly together with nib types assure us that Mentmore made the Golden Guinea. That will do for me. More of a mystery is why anyone was prepared to pay £1.1/- for what is really a fairly ordinary pen when better pens were available for much less. That’s the power of advertising, I suppose.

Platignum is the other house brand of Mentmore. These were proudly sold on their cheapness and undoubtedly outsold all the Swans, Conway Stewarts and Onotos put together. You don’t see them now because they didn’t survive; maybe not always because of poor quality. When the ballpoint came along you would be reluctant to part with your gold nib Onoto and would put it away in a drawer but you would have no hesitation in consigning your old Platignum to the bin.

Platignum’s early claim to fame was its “special alloy” nib. Judging by how few of these have survived and the poor condition in which they have done so, there was nothing very special about it. Like many other base metal nibs of the early days Platignum nibs succumbed to the inks which seemed especially caustic then.

In their last days Platignum took over from Mentmore as the company’s main brand and became respectable, gaining a gold nib. These pens are good writers but still often suffer from plastic shrinkage. That was too much a Platignum tradition to leave behind.