NIELLO (the Italian form of Lat. nigellum, diminutive of niger, " black "; Late Gr. /wXawSv), a method of producing delicate and minute decoration on a polished metal surface by incised lines filled in with a black metallic amalgam. In some cases it is very difficult to distinguish niello from black enamel; but the black substance differs from true enamel in being metallic, not vitreous. Our knowledge of the process and materials employed in niello-work is derived mainly from four writers, Eraclius the Roman (a writer probably of the 11th century), Theophilus the monk, who wrote in the izth or 13th century, 1 and, in the 16th century, Benvenuto Celh'ni 2 and Giorgio Vasari.' The design was cut with a sharp graving tool on the smooth surface of the metal, which was usually silver, but occasionally gold or even bronze. An alloy was formed of two parts silver, one-third copper and one-sixth lead; to this mixture, while fluid in the crucible, powdered sulphur in excess was added; and the brittle amalgam, when cold, was finely pounded, and sealed up in large quills for future use. A solution of borax to act as a flux was brushed over the metal plate and thoroughly worked into its incised lines. The powdered amalgam was then shaken out of the quills on to the plate, so as to completely cover all the engraved pattern. The plate was now carefully heated over a charcoal fire, fresh amalgam being added, as the powder fused, upon any defective places. When the powder had become thoroughly liquid, so as to fill all the lines, the plate was allowed to cool, and the whole surface was scraped, so as to remove the superfluous niello, leaving only what had sunk into and filled up the engraved pattern. Last of all the nielloed plate was very highly polished, till it presented the appearance of a smooth metal surface enriched with a delicate design in fine grey-black lines. This process was chiefly used for silver work, on account of the vivid contrast between the whiteness of the silver and the darkness of the niello. As the slightest scratch upon the metal received the niello, and became a distinct black line, ornament of the most minute and refined description could easily be produced.
The earliest specimens of niello belong to the Roman period. Two fine examples are in the British Museum. One is a bronze statuette of a Roman general, nearly 2 ft. high, found at Barking Hall in Suffolk. The dress and armour have patterns partly inlaid in silver and partly in niello. The dark tint of the bronze rather prevents the niello from showing out distinctly. This statuette is apparently a work of the 1st century. 4 The other example is not earlier than the 4th century. It is a silver casket or lady's toilet box, in which were found an ampulla and other small objects, enriched with niello-work. 6 From Roman times till the end of the 16th century the art of working in niello seems to have been constantly practised in some part at least of Europe, while in Russia and India it has survived to the present day. From the 6th to the 12th century a large number of massive and splendid works in the precious metals were produced at Byzantium or under Byzantine influence, many of which were largely decorated with niello; the silver dome of the baldacchino over the high altar of S. Sophia was probably one of the most important of these. Niello is frequently mentioned in the inventories of the treasures belonging to the great basilicas of Rome and Byzantium. The Pala d'Oro at S. Mark's, Venice, 10th century, owes much of its refined beauty to niello patterns in the borders. This art was also practised by Bernward, artist-bishop of Hildesheim -(ob. 1023) ; a fine silver paten, decorated with figures in niello, attributed to his hand, still exists among the many rich treasures in the church of Hanover Palace. Other nielli, probably the work of the same bishop, are preserved in the cathedral of Hildesheim. In France, too, judging both from existing specimens of ecclesiastical plate and many records preserved in church inventories, this mode of decoration must have been frequently applied all through the middle ages: especially fine examples once existed at Notre Dame, Paris, and at Cluny, where the columns of the sanctuary were covered with plates of silver in the 11th century, each plate being richly ornamented with designs in niello. Among the early Teutonic and Celtic races, especially from the 8th to the nth centuries, both in Britain and other countries, niello was 1 Din. Art. Sched. iii. 27-29 (see Hendrie's edition, 1847). 1 Trattalo dell' oreficeria.
' Tre arti del disegno.
4 See Soc. Ant. Vet. Man. iv. pis. 11-15.
6 See Visconti, Una Antica Argentaria (Rome, 1793).
frequently used to decorate the very beautiful personal ornaments of which so many specimens enrich the museums of Europe. The British Museum possesses a fine fibula of silver decorated with a simple pattern in niello and thin plates of repoussfe gold This, though very similar in design to many fibulae from Scandinavia and Britain, was found in a tomb at Kerch (Panticapaeum). Several interesting gold rings of Saxon workmanship have been found at different times, on which the owner's name and ornamental patterns are formed in gold with a background of niello. One with the name of Ethelwulf, king of Wessex (836-838), is now fn the British Museum (see figure). Another in the Victoria and Albert Museum has the name of Alhstan, who was bishop of Sherborne from 823 to 867. The metal-workers of Ireland, whose skill was quite unrivalled, practised largely the art of niello from == ^ == __ tne lot h to ^e 12th century, and pos- gold and Niello Ring, **& even earlier. Fine croziers, shrines, fibulae, and other objects of Irish workmanship, most skilfully enriched with elaborate niello-work, exist in considerable numbers. From the 13th to the 16th century but little niello-work appears to have been produced in England. Two specimens have been found, one at Matlask, Norfolk, and the other at Devizes, which from the character of the design appear to be English. They are both of gold, and seem to be the covering plates of small pendant reliquaries about i in. long, dating about the end of the 15th century. One has a crucifix between St John the Baptist and a bishop; the other, that found at Devizes, has the two latter figures, but no crucifix. 1 It is, however, in Italy that the art of niello- work was brought to greatest perfection. During the whole medieval period it was much used to decorate church plate, silver altar-frontals, and the like. The magnificent frontals of Pistoia cathedral and the Florence baptistery are notable instances of this. During the 15th century, especially at Florence, the art of niello- work was practised by almost all the great artist-goldsmiths of that period. Apart from the beauty of the works they produced, this art had a special importance and interest from its having led the way to the invention of printing from engravings on metal plates (see LINE-ENGRAVING). Vasari's account of this invention, given in his lives of Pollaiuolo and Maso Finiguerra, is very interesting, but he is wrong in asserting that Maso was the first worker in niello who took proofs or impressions of his plates. An important work of this sort, described at length by Vasari and wrongly ascribed by him to Maso Finiguerra (q.v.), still exists in the Opera del Duomo at Florence. It is a pax with a very rich and delicate niello picture of the coronation of the Virgin; the composition is very full, and the work almost microscopic in minuteness; it was made in 1452. Impressions from it are preserved in the British Museum, the Louvre and other collections. The British Museum possesses the finest existing example of 15th-century German niello. It is a silver beaker, covered with graceful scroll-work, forming medallions, in which are figures of cupids employed in various occupations (see Shaw's Dresses and Decorations of the Middle Ages, 1858, vol. ii.).
AUTHORITIES. The Archaeological Journal of 1862 (vol. xix. p. 323) has an excellent monograph on the subject, see also vol. xii. p. 79 and vol. iv. p. 247; Archaeologia, xxxi. 404; Merrifield, Ancient Practice of Painting, vol. i. (1849) (gives MSS. of Eraclius and other early writers) ; Catalogue of Museum of Royal Irish Academy; Les Nielles a la cath. d'Aix-la-Chapelle (Paris, 1859); Alvin, Nielles de la bibliotheque roy. de Belgique (1857); Duchesne, Nielles des orfevres florentins (1826); Passayant, Le Peintre-graveur (1860- 1864); Ottley, History of Engraving (1816) and Collection of Facsimiles of Prints (1826); Cicognara, Storia della scultura,m. p. 168 (Prato, 1823), and Storia delta calcografia (Prato, 1831); Lanzi, Storia pittorica, ep. i. sec. iii. (1809); Baldinucci, Professori del disegno (1681-1728) and L'Arte di intagliare in rame (1686); Zani, Origine dell' incisione in rame (1802); Labarte, Arts of the Middle Ages (1855); Texier, Dictionnaire de I'orfevrerie p. 1822 (Paris, 1 See Proc. Norfolk Archaeo. Soc. iii. p. 97.
1857); Bartsch. Le Peintre-graveur, xiii. 1-35; Rumohr, Untersuchung der Grunde fur die Annahme, etc. (Leipzig, 1841); Lessing, Collectaneen zur Literaiur (vol. xii. art. " Niellum "); C. Davenport, in Journal of Soc. of Arts (1901), vol. xlviii. (J. H. M.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)