This document discusses interlining and interfacing used in apparel manufacturing. It defines interlining as an additional layer of fabric between the lining and outer shell, while interfacing is a material used between facings and the outer shell, such as on collars and cuffs. The document describes the two types of interlining as non-fusible and fusible, and lists common materials like cotton and synthetic fabrics. It explains that interlining and interfacing are used to support garments, control shape and areas, and reinforce components. The document provides examples of applications, such as using interfacing on jackets and interlining on kameez and lehangas.