I deal with 2 factory brands in Japan for our knits products.
The first one is a brand called UTO
They are specialized in cashmere, and we offer basic V-neck, Crew-neck, Turtleneck, Cardigan in made-to-order service where you get to choose the color, change the length of the sleeves and the body length.
When you deal with wool materials, not only quality of how the products are made, but the quality of the raw materials is extremely important as well.
UTO is very particular about their material, and this is what they say about their cashmere.