Charles and Harold Potter took over Hilton's Paper Mills, the largest paper making works in the world, in 1844. In 1864 James Huntington, a designer for paper stainers and calico printers, joined the company at the Belgrave Mills. In 1853 Belgrave Mill was burnt out and a few years later the Hollins Paper Mill was rebuilt and enlarged. It was there that a laboratory was set up to try and make a reliable water paint.
Paint manufacture commenced in August 1906 and 'Hollins Distemper' was transferred twice daily by horse-drawn wagon to Darwen Station. By 1910 the company was employing six men to travel the country exclusively selling paint. By now it was know as WalPaMur after the initials of 'The Wall Paper Manufacturers' Company. In the same year depots were set up in other parts of the country to ease the pressure on the Darwen factory and speed up distribution. In the same year too the manufacture of oil based paint commenced.
In 1929 the Company took over the paint-making plant of Arthur Sanderson & Sons in London. This was developed into a branch factory to serve the South of England. Expansion in Darwen was achieved when Peel Mill and Cobden Mill were acquired. In 1933 the Walpamur Company (Ireland) was formed in Dublin.
During World War Two Walpamur was engaged on war work producing special paints and dope for aircraft. They were asked to produce 90,000 gallons of white paint for the D-Day landings of 1944. All Allied aircraft had to be painted with white stripes. 30,000 gallons were produced in a week and transported from the factory in a fleet of US Army lorries.