This book contains eight chapters include with references. Chapter one contains the description about the work. Chapter two contains literature survey. Chapter three describes lock stitch formation process. Chapter four contains preliminary investigation of the thesis work. Chapter five contains experimental details of the work. In this chapter a grading system is developed on the respect of some sewing properties. Chapter six contains discussion of results.Conclusion implies that both sewing thread count and SPI affect sewing quality. At present sewing thread count is selected according to the GSM, strength, length, uniformity, elasticity, etc of the fabric. Our research indicates that this approach of selecting sewing thread count is not appropriate. According to our research sewing thread must be selected giving due regards to the cover factor of both fabric as well as sewing thread. Cover factor of sewing thread is related to the count of sewing thread and SPI. Further research may be carried out to develop some mathematical relation so that the count of sewing thread can be worked out from the fabric constructional parameters.