This chapter provides a comprehensive overview of wet processing techniques in the textile industry, emphasizing sustainability as a core theme. Wet processing encompasses a series of chemical and mechanical treatments that are designed to enhance fabric performance, aesthetics, and usability while addressing the industry's growing responsibility to minimize environmental impacts. The chapter is structured into distinct sections, each highlighting the processes, machinery, and sustainable practices that define modern textile finishing. Each section highlights emerging and alternative technologies along with helpful hints on innovation and marketing opportunities. 

The introduction outlines the scope and importance of wet processing, with a focus on the integration of sustainable technologies and eco-friendly practices in transforming raw textiles into functional and high-quality materials. The pre-treatment section discusses key preparatory steps, including desizing, scouring, and bleaching, and explores sustainable alternatives such as enzyme-based treatments and plasma treatments. The dyeing section examines the application of colour through traditional and innovative methods like foam and spray dyeing. The focus is on reducing resource consumption with approaches like plasma-enhanced dyeing and dyebath reuse. In the printing section, techniques such as screen, rotary, and digital printing are explored, emphasizing sustainable practices like reducing chemical waste through precision and automation. The finishing segment highlights mechanical finishes like compacting, brushing, sanforizing and heat-setting, along with chemical finishes such as water-repellence, flame retardants, anti-microbial properties and decorative denim washing. A focus is placed on using bio-based finishing agents and energy-efficient machinery to align with sustainability goals while enhancing fabric usability.

The structure of this chapter integrates theoretical concepts with industrial practices, offering a balance of scientific understanding and practical application. By the end of this chapter, readers will gain a holistic understanding of wet processing, its impact on textile properties, and its role in meeting industry and consumer expectations.