If you are a spinner, or thinking about starting to spin then this is a great resource for you. I am just starting in spinning, I did give it an effort years ago but this is a real start to spinning for me, and I am very curious about all of the different types of fibers out there. For example, I did not know how sensitive cotton is to pressure. I was not aware that the labor intensive process of obtaining fiber from flax eventually yields linen. I was unaware of how sensitive hemp and linen are to acid. I have learned so much from this book, and the entire series really. I recommend these to anyone thinking of getting involved in fiber-works, even if they are not spinning some of the aspects of different fibers greatly effect how you will use them and care for them.