This video is a quick introduction the process behind machine sewing. Unlike sewing by hand, which uses 1 thread, machine sewing requires 2 separate threads: the top thread and the bobbin thread.

When applied to machine embroidery, this means that the top thread will be the visible/front side of the finished patch, while the bobbin thread is visible only on the backside of the work. Therefore, the top thread color will be changed for every separate color of your design, whereas the bobbin thread will remain the same - usually either white or black to best match your chosen fabric color.