Complex sentence: The enamel is mostly in "ronde bosse" technique, applied to three dimensional figures, with white as the dominant colour; white enamel using lead was only recently developed, and very fashionable, dominating many contemporary "ronde bosse" works.
Split into simpler sentences: The enamel is mostly in "ronde bosse" technique, applied to three-dimensional figures, with white as the dominant colour. White enamel using lead was only recently developed, and very fashionable, dominating many contemporary "ronde bosse" works.