Masterblend will be natural fur with antron added for those who appreciate the benefits of antron. Masterblend has finally undergone a long overdue revision. It was originally developed for H.L.Leonard Rod Co. to compliment the books of dressings popular at that time. Through the 70’s and 80’s; additional blends were added, and several compliments of synthetic blends were developed. More up-to-date works have replaced the original books.