Depending on what you want to do. It won't show you how to sew anything. However, it does have great pictures in clear black and white showing what people wore in all different classes of society from about 1485 to 1601, carefully documenting changes in high fashion and also showing differences in different countries (England, Spain, France, Germany). I could recognize many of the portraits he used, as a historian of the time, but his drawings made what was actually being worn more clear than in portraits. You couldn't sew a costume just using his pictures, but if you had a pattern from somewhere else, his pictures would make it look more accurate. For details of sewing techniques, and photos of actual period clothes .I would go to Janet Arnold. I think that they supplement each other well. But neither is really a pattern book (except maybe if you are much more advanced than I am).