The National Society of Operative Printers, Graphical and Media Personnel was formed in 1889 as the Printers' Labourers' Union. In 1899 the union adopted the name Operative Printers' Assistants' Society and in 1904 it became the National Society of Operative Printers' Assistants. In order to reflect the inclusion of skilled workers the union finally became the National Society of Operative Printers and Assistants in 1912. NATSOPA was particularly strong in London, a factor which enabled the General Secretaries Isaacs (1909-48) and Briginshaw (1951-75) to maintain effective central control over the union's affairs and to guide NATSOPA's politics accordingly.
NATSOPA pursued a policy of amalgamation and absorbed the Revisers and Readers' Assistants' Society of London in 1916 and the London Press Clerks' Association in 1920. In 1914 the Stereotypers and Electrotypers' Assistants' Society dissolved itself and its members joined Natsopa as the London Electrotypers and Stereotypers Branch. In 1919 Natsopa came to an agreement to transfer this branch to the National Society of Electrotypers and Sterotypers. It was not until 1966 that NATSOPA entered into a formal merger process with another sizeable union, namely the National Union of Printing, Bookbinding and Paper Workers. The two unions came together under an umbrella organisation called the Society of Graphical and Allied Trades. Both unions maintained their independent structures. The National Union of Printing, Bookbinding and Paper Workers became the Society of Graphical and Allied Trades Division A and NATSOPA became the Society of Graphical and Allied Trades Division 1. The aim was to achieve a complete merger over time but differences led to in-fighting and in 1972 the two divisions split. Division 1 became the National Society of Operative Printers, Graphical and Media Personnel (retaining its former acronym NATSOPA) whilst Division A retained the name Society of Graphical and Allied Trades.
Following the split with SOGAT in 1972, the Sign and Display Trades Union transferred its engagements to NATSOPA. In 1982 NATSOPA and SOGAT 1975 (so called after amalgamation with the Scottish Graphical Association in 1975) finally agreed terms and joined together to become SOGAT 1982. The culmination of all these amalgamations occurred in 1991 when SOGAT 1982 and the National Graphical Association (1982) joined together to form the Graphical, Paper and Media Union.