Lenovo ThinkPad Reserve Edition - Manual (Page 21)

2. Occasionally treat the cover with oil. First, try a very small amount of
leather-coating oil in an inconspicuous position on the cover. If the oil
does not stain or discolor the leather, apply a small amount of the oil on
the entire surface of the cover.
Taking care of your ThinkPad computer
Chapter 2. Taking care of your ThinkPad Reserve Edition computer
11