A calfskin leather finished by a process which originated in Russia, whence the name was taken. Birch oil or tar forms a component part of the dressing which gives the leather a peculiar fragrance. It was originally bark-tanned, although the name is now applied also to chrome-tanned calfskin. The Russian “Russia” was usually dyed a deep red, and in this color is still often used for the binding of fine books. The grades which are made for use in shoe manufacturing are heavier and less expensively finished. They are usually finished in tan or brown, although black Russia has been more used of late years.
The color has no connection with the name. It is the confusion of the name “russet” which leads to the occasional use of the term Russia in referring to calfskin of some other tannage or finish. It is said that the birch oil was originally used for a double purpose, one being to soften the leather and the other to protect it from insects.
— The Shoe and Leather Lexicon, Fourth Edition, 1918