After trying every type of leather preservative I could find, I settled on Pecards. I have been using it for some 30 years now with good results. The secret is to use it as sparingly as possible. The old adage of "if a little does a little good, a lot should do a lot of good" doesn't apply. I rub it in on the smooth side of the leather in coats as thin as I can spread it out. Let this work in before applying another coat. Depending on how dry the leather is, it may take several applications to treat the leather. Don't use heat or sunlight to try and speed up the process. I have found that when Pecards is used sparingly, the change in the color of the leather is minimal, and in some cases it gives dried out leather a healthier color.