Émile Gallé is considered to be one of the major innovators in the French Art Nouveau movement and was a founder of the École de Nancy or Nancy School.

Cased glass and cameo glass were two techniques often used by Gallé. Cased glass was made of two different layers of glass of different colors, fused together by heat. The first case of layer is made in a cold. When it is finished and cooled, a second layer is blown inside the first Then the piece is placed into the furnace, so the two layers fuse together. This could be repeated for multiple layers of glass. Cameo glass was a means of decorating cased glass. The cased glass of two or more colors was carved with a diamond saw or etched with acid, so that the colors of the layer underneath were visible and created a design. Enamel glass was decorated on the outside by a brush of enamels colored by metallic oxides.

Gallé continually experimented with new techniques of glass art. One of his major innovations was glass marquetry, or applying layers of glass on an object. He attached then sheets of colored glass onto a hot glass object He could join the laminations or overlay them, adding an infinite number of layers and colors.