Butterfly chairs are often much-loved. To add to the fun of your much-loved butterfly chair, you might want to "marry" it with a leather cover.
Leather gives "that smell", that "leather-y-ness", that grain.
There are many ways to cover a butterfly chair -- many types of coverings -- but the best way -- the way with the most class -- is with leather.
Have a read here about leather butterfly chair covers.