Greater minds than mine —
If one browses the net for pens, and comes upon a casually-photographed Sheaffer — one that, to an untrained (or only semi-trained) eye, looks as though it might be either an Imperial or a PFM — what are the best chances to differentiate the two?
Obviously if the filling system is specified or displayed, that will make it clear. Often, though, I see just the shape of the thing: familiar profile, wide band, somewhat chiseled-looking blind cap.
Is there a way to differentiate the two lines on the basis of a careless photograph?