M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)

Analysis - JÁRÓ Márta, GONDÁR Erzsébet: Mediaeval membrane threads used for weaving and embroidery

2. Historical review Membrane threads are reported to have appeared in Europe as important items from Byzantium or the island of Cyprus (or after calling at ports there) in the 11th century by some sources [1—3], while others opt for the 12th century [4, 5]. The labels attached to them by 12th century inventory data refer to their origins: aurum filatum de opère cyprense, or de Chypre as well as aurum filatum de opère Romanie [6]. Being less expensive, flexible, lightweight and easy to work with, membrane threads displaced for centuries the threads made of pure gold or gold alloy in Europe. At first their application was confined to Southern Europe (Sicily and Andalusia) but in the 13th c. it spread to the North-Italian textile centres (Lucca, Venice, Florence, Genoa, Bologna) as well as the German workshops (e. g. Cologne). From the second half of the 14th c. onwards North— Italian workshops gradually shifted to using gilt silver threads while the application of membrane threads was retained for pieces coming from Germany as well as from other European countries (e. g. Hungary) until as late as the beginning of the 16th c. In Bock's view they were imported from the East all along, although he does not discard the possibility that by the 15 th—16th cc. the technique involved in making them could have been known [7]. Falke however, relying on data provided by Heyd, claims that gold spinners were able to produce such threads in Lucca as early as the 13th c. and later in Genoa, Venice, Milan and Florence, too [8]. Weibel points out that they were produced in Cologne and Bologna [2] while Geijer refers to the fact that they were supplied by Cologne and sent to Lucca [9]. 3. Production of membrane threads as described in the literature In the 20th-century reference books on textile history that we have surveyed, all that is said about the making of these threads is that animal membrane was gilded or plated with silver following which it was cut into strips and wound around silk or flax yam. 3.1. Quality of threads As to their quality, two kinds of thread are described. Falke reports on the Byzantine membrane thread as being thin and heavily gilded; the extremely narrow strips of coated membrane were wound around yellow silk thread. As for the Cyprian membrane thread, the relatively broader strips of membrane were wound around a thicker flax yam [8]. According to Braun-Ronsdorf the thread originating from Byzantium was the thicker one [10]. The quality of threads produced in Italy and the German territories is referred to only by Weibel and Geijer. Weiber states that the Cyprian gold thread was finer and, of course, more expensive than the ones from Bologna and Cologne [2].Geijer claims that the filament of Spanish-Islamic silks originating from an earlier period was wound around silk while the type known to have come from Italy at a probably later stage was wound around a somewhat thicker flax or hemp yarn [5]. 3.2. The winding of metal-coated membranes Braun Ronsdorf points out that metal-coated membrane was probably wound around the core in the moist state since it is very difficult to separate the two [10].