This chapter describes different aspects that are connected to textile testing and measuring of textile properties. Textile material properties are tested for various reasons, for example, to obtain information that assists in material innovation and selection, to help to oversee the agreed level of production, and to secure that the final products fulfill the properties that are pledged for them. When talking about textile testing, the concept of quality is also concerned. What is quality and how can it be described? In this chapter, the aspects of quality are discussed first.