Unique bowl designed by Andries Dirk Copier in 1943 for Glass Factory Leerdam. The thick colourless glass bowl is mould blown and decorated with veils of air bubbles and shot through with deep reddish purple tints, which results into a spectacle of colourful ever changing ‘dancing’ light effects when the bowl is displayed in sunlight. This one-off piece by Andries Dirk Copier has a pontil mark and a diamond-incised signature on the underside: “LEERDAM UNICA” V 905 A.D. Copier. This item is described and documented in the publication 'Andries Dirk Copier. Ideas in Glass. Unica and more' by Dieter Enke (publisher: Arnoldsche, 2009).