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The objective of this research project is to investigate novel concepts of determining fibre assembly mechanical properties at woven fabric at meso-scale, viz. yarns and unit-cell. In order to carry out this investigation three instruments were developed and these are presented in subsequent chapters of this thesis. Initially, an instrument was built in order to explore the buckling technique on yarns and fabrics. The data obtained was converted into pure bending output through a proposed non-linear planar elastica model. It was found that the data obtained were in agreement with data obtained from other measuring technique already available in the industry, viz. Pure Bending tester (KES FB2) from the Kawabata Evaluation System. This investigation also found that the buckling technique offers some advantages when compared with the bending tester. Furthermore, the yarn compression method was also explored. A Yarn Compression tester (YCT) was developed in order to carry out this study. This instrument induces transverse compression upon the yarn by means of a probe, which results in a compression versus thickness curve. An, additional feature was introduce on the YCT, such as the use of a digital camera that allows the yarn lateral spreading to be determined as the yarn is compressed. This feature may be used to calculate the Poisson’s ratio, which can be used as an input value for future compression models. Good agreement was found between the proposed yarn compression technique and data obtained from the Kawabata compression tester.Finally, yarn torsional technique was explored by means of developing a Yarn Torsion tester (YTT). It was found that data obtained for this instrumentation were in agreement with a linear model proposed by Postle et al. This investigation may allow future research to continue by means of proposing a torsion mathematical model.