Polypropylene is an important thermoplastic fibre. It enjoys a prominent status next only to polyester in the synthetic fibre domain. This fibre has some excellent properties which are even considered superior to nylon for carpet use in terms of soil repellence and other related attributes. However the polyproylene fibre has not made significant dent in the apparel sector due to inherent properties such as hydrophobicity, poor handle properties and absence of satisfactory dyeability. The important way for entry of polypropylene into the apparel sector is through texturizing process, which improves the feel and increases water retention ability of polypropylene yarn. It is therefore of significant interest to researchers to understand the effects of colourants and carrier used for mass colouration on the texturizability and fibre properties. In this book, studies on three types of coloured polypropylene yarns, viz grey, coal grey and black have been reported. This book also presents optimized texturing parameters for white and coloured polypropylene yarn. The effect of secondary heater temperature and stabilizing over feed has also been reported.