The earlier chapters dealt with the production of yarns where the objective is to provide as regular and as parallel as possible an arrangement of fibers twisted together to form a continuous length of uniform thickness. Slubs, neps, thin places, and so on are noted as faults and imperfections and are viewed as degrading features of yarn quality. A great deal of care and effort is taken to minimize their occurrence by preventing or removing these features wherever possible. In fancy yarn production, these features are deliberately introduced into the yarn, along with color, to give visually and texturally attractive differences to fabrics. Some yarns that might be called fancy yarns have only color changes as distinctive features, obtained by a number of techniques such as twisting together different colored yarns, spinning irregularly blended dyed fibers or printed slivers, and irregularly printing already spun yarns. The production of such yarns will not be considered here, since the processes described in Chapters 2 and 3 are generally used to make them. In this chapter, the fancy yarns that are of interest are the ones that may be said to have, besides color changes, a specially structured profile and therefore conform to the following definition:

Definition: A fancy yarn is a yarn that is made with a distinctive irregular profile or a construction that differs from basic single and folded yarns, the objective of which is to enhance the aesthetics of the end product with respect to visual and textural properties.