Also known as tucking or walking, is a step in woollen clothmaking which involves the cleansing of cloth (particularly wool) to eliminate oils, dirt, and other impurities, and making it thicker. The worker who does the job is a fuller, tucker, or walker, all of which have become common surnames. The Fulling or Tucking process consists of the closing together of the threads of newly woven woollen fabric with the assistance of soap or acid liquor, with the end purpose of producing a grease free cloth of the correct thickness for future use, including dying. After a piece of woollen cloth has been first woven, the fibres of its fabric are loose, airy and unmeshed, and similar in texture and appearance to a piece of cheesecloth or sackcloth, and the cloth, clinging to its fibres, still retains a significant amount of oil or grease, introduced during the weaving process. Since oils and grease will inhibit the binding action of the dyes, these need removing.

There were a number of fulling mills on the River Aln, with Walkergate indicating that a number were probably in this area. The main fulling mills were Abbey Mills, Hulne Prioy Mills, Lowther’s Haugh, Hesleyside and Peter’s Mill.