During the Universal Exhibition of 1900 Daum was awarded a ‘Grand Prix’ medal. Daum glass became more elaborate. Acid etching (by Jacques Grüber) was often combined with carving, enamelling, and engraving on a single piece of glass to produce creative glass masterpieces. The most complicated creations also featured applied glass elements, such as handles and ornamental motifs in naturalistic forms. The Daum brothers soon became a major force in the Art Nouveau movement, seriously rivalling Gallé, so much so that when Émile Gallé died in 1904 they became the leaders in the field of decorative glass.