Kolinsky refers to a type of Asian weasel / mink. Historically probably from the Kola Pinninsula of northwest Russia, near Finland. Sable is a type of marten (small, sleek long animal). They are in the same Family and are closely related animals.
Picture by Elena Lapshina
It's fur is coveted because it's smooth and glossy from every direction that it is stroked. When stroked opposite the grain, fur from other animals feels rough. But enough of the sable. Let's talk about paintbrushes.
aka Siberian weasel
aka red sable
The Siberian weasel is an amazingly animal that lives in forests from Siberia to Eastern Asia. It lives near rivers and lakes. It's a hunter. In some places, it's considered a pest because it kills chickens and muskrats in farms, more than it can eat.
The best hair comes from northern Siberia, where harsher winters means the winter coat is long and thick.
The Siberian weasel is NOT an endangered species. I looked at WWF, IUCN and CITES to confirm this. However, it is placed in the endangered animals category and is subject to CITEs.
Winsor & Newton says that its natural hair brushes are obtained from sustainable sources and animals are not sourced for the sole use of manufacturing its products.