Two Italian chairs decorated in "certosina", 17th and 18th century.

False pair of Italian walnut chairs, one smaller (118x47) from the 17th century, the other slightly larger (124x46) from the 18th century.
Both have the same decoration "a Certosina", a kind of mosaic created from pieces of wood, mother-of-pearl, bone, or ivory.
This technique, widely used in the Italian Renaissance, is named after the convent of Certosa, near Pavia, where it was first used to decorate an altarpiece.