This book gives a complete insight of natural fibres which have been used since the beginning of civilizations when straw was used to reinforce clay to make houses. Up until a century ago, natural fibres had lost their usefulness in industrial applications. It has been a few decades now since natural fibres have found attention again. They are being used in polymer based composites as reinforcement and as a perfect alternative to artificial fibres which are hazardous to the environment due to their non-degradability. In this book, a detailed procedure is discussed for fabricating composites by using jute as reinforcement and polypropylene as matrix. SEM analysis is depicted which is performed on the broken samples from the tensile tests to find out the mechanism of failure of the composite under tensile load.