Tape sizing is the process of adding polymers and wax to cotton yarn in order that it will be less likely to break when being woven.
In the 19th- and early 20th-centuries, tape sizers were regarded as being the most skilled workers in the cotton industry and therefore were able to command relatively good wages and conditions of employment.
[1] By 1894, ten local unions held membership of the amalgamation, although as all were very small, it represented a total of only 910 workers.
Early in the 1900s, it added "South Lancashire" to its name, probably in the hope of persuading the rival Amalgamated Tape Sizers' Friendly Protection Society to affiliate, although this Ashton-under-Lyne based union did not do so.
The Tape Sizers would conduct all trade union business, while the Preparatory Workers would only deal with matters relating to property.