De waardefactoren
Een taxateur weegt bij deze categorie een vast aantal criteria. Hieronder leggen we ze uit, in de volgorde waarin ze doorgaans worden bekeken.
Enamel condition — the critical factor
Art Nouveau relies heavily on enamel in various techniques: cloisonné (with metal separations), champlevé (in excavated sections), and the most valuable plique-à-jour (enamel without a metal backing, allowing light to pass through like stained glass). Every chip, every crack, and every missing enamel part directly and significantly reduces the value — a completely undamaged plique-à-jour surface is almost technically impossible to reproduce.
An appraiser will examine under magnification whether the enamel surfaces are smooth and intact, if there are hairline cracks, and if there are traces of later retouches (different colour, different gloss level). For plique-à-jour, the transparency itself is also important: any interruption in its light-transmitting character is detrimental.
Signed versus anonymous
The great names — René Lalique in Paris, Philippe Wolfers in Brussels, Georges Fouquet, Louis Comfort Tiffany for American work — form their own collector's market with dramatically different price levels than anonymous period work. Signatures must, of course, be verifiable; copies do exist. For authenticity, an independent specialist with auction experience is the recommended route.
Anonymous Art Nouveau work from the same period has its own, separate market. For a large group of collectors, the period-typical design and craftsmanship are more important than the signature — such work is regularly traded between five hundred and three thousand euros, depending on material and completeness.
Design and iconography
<strong>Female profiles.</strong> Flowing hair, soft lines, often sculpted in profile. Signature motif of the movement.
<strong>Insects.</strong> Dragonflies, butterflies, bumblebees — often executed in plique-à-jour. Highly collected.
<strong>Flora.</strong> Orchids, irises, poppies, thistles. Complete floral compositions without missing leaves are rare.
<strong>Symbolist motifs.</strong> Snakes, peacocks, swans. Often in combination with opals or moonstone — period-typical.
Material and stone choice
Art Nouveau consciously works with 'softer' materials: opal, moonstone, ivory (now trade-restricted), horn, enamelled gold. The artists chose light effect and symbolism over brute stone value. For an appraiser, this means that conventional valuation (diamond + heavy gold) is less applicable; design, execution, and completeness of the enamel parts determine the majority of the value.