The Operative Bleachers, Dyers and Finishers Association, also known as the Bolton Amalgamation, was a trade union representing cotton finishers in the vicinity of Bolton.

The union was founded in 1866 in Bolton and by 1871 already had more than 1,000 members. In its early years, it focused on paying welfare benefits to members and promoting their high skill levels. By 1892, the union was also organising in Bury, Chorley, Great Lever, Middleton and Pendleton, and its membership had grown to 3,583. That year, it launched its first strike; this was followed by further strikes in 1893 and 1895, which ultimately achieved a standard wage structure.^[1]

The union continued to grow under the leadership of Alfred Smalley, and appointed Robert Kay as a full-time organiser. It had 4,700 members in 1904, and more than 11,000 in 1910.^[1]

In 1936, the union merged with the Amalgamated Society of Dyers, Finishers and Kindred Trades and the National Union of Textile Workers to form the National Union of Dyers, Bleachers and Textile Workers.^[1]

The union sponsored a Labour Party candidate in two Parliamentary elections, on both occasions in seats which the party had never previously won.^[2]

1900s: Alfred Smalley

1915: Gilbert W. Jones

1931: Charles Hewitt