The idea of making a pocketknife handle out of 'bumped' or stamped sheet steel goes back long before WW-I. It was evidently patented in Germany, but I have not yet seen a US patent for the invention -- one or more might exist, but I have not found them.
Those early versions had the sheet steel embossed to look like bolsters, with 'stag' in the center. The stag part was painted brown or black. They were cheap to make, and looked it, plus the handles tended to work loose, so they were not very big sellers -- even at a nickel or dime apiece.
In 1934 this concept was revolutionized by Otto Stiehl and Ernst Lohr of Solingen. They made sheet steel handles with the centers slightly recessed, allowing thin sheet celluloid to be wrapped around each handle, giving the appearance of a solid handle and bolsters, good enough to fool the average consumer, especially since these knives could be retailed profitably for around a quarter of the wholesale cost of a solid knife. This turned out to be the most profitable invention in the history of cutlery. It was patented in every country with a patent system.
E. Lohr & O. Stiehl had their own company, ELOSI (their initials) but their real money came from licensing the patent to bigger companies. In Germany the primary licensee was Gebruder Richartz. In Britain it was Richartz's sister firm, Richards Brothers.
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