Mink oil is a common sight in shoe stores and other places that sell leather boots. It is a useful part of caring for your boots, so it can be helpful to understand what mink oil is and what, precisely, it is used for.
Mink oil is a natural oil derived from mink fat. It is commonly sold as a paste or cream for leather conditioning and is an ingredient in many cosmetics.
Mink oil is made out of the thick layers of fat left over when minks are killed and skinned for their pelts.
The primary benefit of mink oil on leather boots is as a softening agent. Rubbing mink oil into new or otherwise stiff boots helps make the leather more supple and comfortable.
Mink oil improves the lifespan of leather by replacing the natural oils removed from the hide during the tanning process, as well as making the leather more water-resistant.
It is possible for mink oil to over-soften boots, making them less supportive to the wearer's ankles. This is especially true if the leather is chromium-tanned. Mink oil can also slightly discolor leather, making it darker.
- "Leatherworking Handbook: A Practical Illustrated Sourcebook of Techniques and Projects" by Valerie Michael