Silk, the queen of textiles, is popularly used in high-fashion clothing and is primarily produced in Asia. The mulberry silk, a cultivated variety known for its elegance, is blended with cotton to make it more affordable. Morphologically, silk consists of 70–80% fibroin, surrounded and covered by another protein of different composition, known as sericin (20–28%). Yarn preparation is one of the most crucial stages in producing high-quality silk fabric. Hence, selecting high-quality silk fibre, maintaining optimal process parameters, and verifying quality standards at every stage are crucial. The quality of silk and its grading system are essential in establishing a standard to facilitate a fair and equitable transaction of raw silk that helps twisters and weavers identify appropriate lots and suppliers. The inspection certificate provided by the supplier sometimes contains insufficient information; therefore, additional testing must be carried out to use those yarns in high-speed looms. Nowadays, Indian silk exporters emphasise the quality parameters needed to compete in the international market. The present chapter primarily focuses on comprehensive practical information regarding the quality of raw silk and its testing, as well as the yarn formation processes that occur before degumming and dyeing, since producing good yarn ultimately yields better quality products.