Occupying a historic factory on Barskimming Road in Mauchline (South Ayrshire), Kays of Scotland have been suppliers of precision-made competition-standard curling stones since 1851, which are now exported around the world. The sport of curling has its origins in Scotland, probably dating back to the 16th C. when the monks of Paisley Abbey are recorded as having played a game whereby they slid stones across the ice. The game has similarities to lawn bowls, but is also described as 'chess on ice'. Although other countries claim to have invented the sport, this seems unlikely as the principal contenders are the Low Countries, where suitable stones are rare indeed. As the rules of the sport developed, Kays were instrumental in setting the standard weight of 40 pounds (18.1 kg) for curling stones, a specification now adopted internationally.
Kays have the exclusive rights to take granite from the island of Ailsa Craig in the Firth of Clyde. This island is home to unique forms of micro-granite particularly suited to the sport. Approximately once per decade, the company 'harvest' around 2000 tons of the stone to meet their production needs. The stone is transported by road to Aberdeen to be sawn into thick slabs before being returned to Mauchline for processing. Kays of Scotland are now one of only two manufacturers of curling stones in the world, and the only ones to use stone from the island. There competitors are the Canada Curling Stone Co. of Komoka Ontario, who import granite from Trefor Quarry in Wales.
Kays occupied their current site in 1911, moving from their original water-powered mill at Haugh on the north bank of the River Ayr, 1¼ miles (2 km) to the south. They remain a family-owned business. The company has a highly-skilled workforce and, although extensive use is now made of machinery in the processes of cutting, shaping and polishing the stones, the hand and eye of the expert remains key to the finished product. Kays manufacture stones using a conjunction of two different types of Ailsa Craig granite. The body comprises Common Green Granite, which is tough and particularly resistant to splintering when it hits another stone in play. A hole is cut through this body, to create a doughnut shape, and this hole is filled with a core of dense Blue Hone Granite, known as an Ailsert. It is the base of this core which makes contact with the ice, and it effectively resists abrasion.
Kays have supplied curling stones to every Winter Olympic Games since Chamonix in 1924, with the exception of the 2002 event in Salt Lake City.
