Footwear has been made at Northamptonshire Productive Society (NPS) with various different construction methods, including riveted and stitched, stuck-on, vulcanised and more recently Goodyear-welted, which is now used in all our footwear production.
In the 1950's Dr. Maertens and his associate Dr. Herbert Funck developed a now famous air cushion sole. R. Griggs and Company Ltd., who owned the rights to manufacture footwear with this technology, sought out the best local factories to manufacture footwear using this sole.
NPS was an obvious choice and in 1959 some sample boots with air-cushioned soles were welted for Griggs' factory.
For 35 years NPS produced Solovair (Sole-of-Air) boots and shoes under licence, which were sold under the name ‘Dr Martens by Solovair’.