Imperial Chemical Industries plc came into existence in 1926, following the merger of Nobel Industries Ltd, Brunner, Mond and Company Ltd, the United Alkali Company, and the British Dyestuffs Corporation. The new company was called Imperial Chemical Industries Ltd. Its operations began in 1927, with 33,000 people employed in five main product areas: alkali products, explosives, metals, general chemicals, and dyestuffs. In 1928, its head office opened in Millbank, London. The former British Dyestuffs Corporation works at Blackley, Manchester became the home of ICI's Dyestuffs Division. The main factory for the General Chemicals Division was at Billingham, County Durham. ICI's Research and Development Department developed a number of significant products in the early 20th century, including the acrylic plastic Perspex in 1932, Dulux paint (in partnership with DuPont) in 1932, polyethylene in 1937 and polyethylene terephthalate fibre (known as Terylene and PET) in 1941. The work on polyethylene was led by the Dyestuffs Division at Blackley until a new Plastics Division was established at Welwyn Garden City in 1937. In 1971, the Dyestuffs Division merged with parts of the Nobel Division to become known as the Organics Division. Later mergers with other specialty chemical producers created ICI Colours and Fine Chemicals, which then became ICI Specialties. From 1940, ICI Dyestuffs was involved in the manufacture of Nylon fabrics at its Huddersfield plant, and in 1964 the company established ICI Fibres to manage its successful textile, fibres and Nylon production. The Nylon part of the business was sold to DuPont in 1992. In 1944, as Imperial Chemical (Pharmaceuticals) Ltd, the company was involved in the development of penicillin at its Trafford Park works. Because of its success with pharmaceuticals, the company established ICI Pharmaceuticals in 1957. In 1993, ICI Pharmaceuticals and other bioscience divisions became Zeneca, along with ICI Specialties. Zeneca merged with Astra AB in 1994 to form Astra Zeneca Plc. General Chemical production continued until the acquisition of ICI by Akzo Nobel in 2007.

Gartside & Co (of Manchester) Ltd, previously known as John H. Gartside and Co Ltd, had mills in Ardwick, Manchester, Wellington Mills, Ashton-under-Lyne and had a dye works Buckton Vale Print Works in Carrbrook. The Buckton Vale Print Works became the largest bleaching, dyeing and calico printing works in the North West by the end of the 19th century. The works, previously owned by a Mr Reynolds, was acquired by John Gartside and John Nield in 1866 at which point rapid expansion of the works began with the absorbing of Middle Mill, a previous mill on the site. The works eventually straddled both banks of a brook, from which the water was collected in reservoirs and utilised for the dyeing and printing processes. In 1899 the Buckton Vale Print Works became part of the Calico Printers Association and was renamed the Calprina Works. In 1981 the works suffered an explosion, prompting the closure of part of the site. By 1999 Calprina had been acquired by the Leeds Group plc and the printing machinery was moved to Leeds. The print works closed in the late 20th Century and the site cleared , with the reservoirs remaining a landscaping feature.