SMALTO. – In goldsmiths’ workshops, enamels have always, in every period, been extensively used for the decoration of objects. The glass paste, variously colored with metallic oxides and fused, is applied over metal sheets by different procedures according to the period and the schools.
I. S. INCASSATO (cloisonné). – According to this technique, the glass paste is enclosed in cells formed in accordance with the design and with the chromatic varieties of the individual areas. The technique, of Persian origin, passed to the barbarian workshops as part of the body of experience derived from late Roman civilization (fibulae in the Museo civico di Torino, the ampulla of Pinguent, Vienna, Museum; the crown of Teodolinda, Monza, cathedral treasury, etc.).
In Byzantium this technique continued, but with the achievement of exceptionally clear transparency in the colors, harmonious movement in the golden line of the outline, and perfect chromatic inlays (a group of enamels belonging to the oldest altarpiece of the cathedral of Venice, 11th century; reliquary of the Tesoro di S. Marco, etc.). Thus both at Montecassino and at Palermo, through the work of Byzantine goldsmiths and imitators, the technique was applied to rich sacred and secular goldwork (the crown of Costanza normanna, Palermo, Cathedral; mantle for the coronation of the Norman kings, Vienna, Kunsthistorische Museum). In the other enamels with figurative motifs, the frequency of the gold wires forming the cells broke up and recomposed the surfaces in a stylistic rhythm that was imitated in painting until the late 13th century (Cimabue, Duccio). Among the works executed in southern Italy and Sicily are: the reliquary Cross in the cathedral of Naples; the Cover of an evangeliary in the cathedral of Capua; the Mitre in the cathedral of Scala; the Cross of Gaeta; the Cross of Cosenza; the portable altar of Agrigento, etc. Adopted directly and indirectly through contacts with the works of the Mosan and Rhenish workshops, this technique was developed, through the graduated coloring of the enamels, toward more plastic effects by the school recently located in Lombardy, to which would belong the binding of the Ariberto codex of the 11th century (placed in relation to the binding of the cathedral of St-Denis at the Louvre), the binding of the cathedral of Vercelli, the Pace of Chiavenna, etc.
II. S. AD INCAVO (champlévé). – The technique developed in the northern workshops, but of Roman origin, consists in pouring enamel onto copper plates hollowed out according to the design, but lacking actual cells. At first (12th century), the figure or decoration was colored with enamel, leaving the natural color of the metal for the background; then (at the beginning of the 13th century), the tone of the metal was reserved for the decoration and the background was colored with enamel. Under the pressure of the sculpture, the figure was also modeled, wholly or in part, in copper and superimposed on the enameled surface. Using this technique, the workshops on the Meuse produced enamels for works of goldsmithing such as the Golden Cross (10th century) and the Reliquary Chest of S. Servatius at Maestricht, the portable altar of Stavelot at Brussels (Musées Royaux d'art et d'histoire), etc., always with rare expertise. A new decorative repertory gradually took shape: through contacts with the goldsmithing of Spain, Islamic motifs arrived, while other motifs passed over from the checkered backgrounds of French miniatures. Inscriptions in pseudo-Kufic characters, slender branches with flowers, circles, and little crosses adorned the sacred and secular objects produced by the workshops of Limoges, which spread throughout Europe in great numbers, also giving rise to various centers of imitation in Spain and Italy (numerous examples in the Musée de Cluny, at the Louvre, in the Museo Cristiano Vaticano, at the Bargello, in the cathedral of Agrigento, etc. Among the derivatives are: the Arca of S. Domingo at Silos, a product of a Spanish workshop; the enamel of the ciborium of S. Nicola in the cathedral of Bari; the Cross in the Museo di Catania, etc.). These enamels too, executed in a chromatic range varying from blue to sky blue, with greens and reds, transmitted to 13th-century painting influences and certain survivals of Byzantine iconographies, more frequent in Limoges works, and of Ottonian iconographies in the workshops on the Meuse.
III. TRANSLUCENT ENAMEL
In Italy, principally at Siena, a new technique emerges in the second half of the thirteenth century, after Guccio di Mannaia had provided its first example in the famous chalice of Niccolò IV (1288–92) in the cathedral of Assisi; this technique soon spread throughout Europe, that
SMALTO - Plaque with a reserved figure on a blue ground depicting a falconer on horseback. Detail of the left side of the casket of Cardinal Gualà Bichieri, with Limoges champlevé enamel (first quarter of the 13th century). Formerly preserved in the Abbey of S. Andrea at Vercelli, now privately owned.
Among the masterpieces are the reliquary of the Most Holy Corporal in Orvieto Cathedral, executed by Viva and Ugolino da Vieri, and the reliquary bust of s. Agata, executed by Giovanni di Bartolo of Siena at Avignon for the cathedral of Catania.
IV. S. DIPINTO. - Mentre la tecnica dello s. traslucido riceve numerose applicazioni anche nella oreficeria sia chiesastica che civile, già nella metà del '400 a Limoges comincia la nuova tecnica che consiste nel dipingere con lo s. fuso sulle lastre di rame. Operarono con questa tecnica, spingendola alla massima perfezione, i maestri Pénicaud, Léonard Limousin, Pierre Reymond, ecc. e la loro produzione mantenne sempre qualità di arte.
In Italia massimamente nel '700 la pittura a s. venne usata per medaglioni sacri, per tabacchiere, per vari oggetti. Nell'oreficeria dell'Ottocento che già comincia ad essere eseguita in serie, gli s. scompaiono mentre vengono ripresi con adattamenti del tutto nuovi dall'oreficeria moderna massime di Francia, preferendo le tecniche più antiche che lasciavano allo s. il pieno arbitrio di comporre pure e semplici intarsiature cromatiche. - Vedi tavv. LII-LIII.