Conservation around the Millennium (Hungarian National Museum, 2001)
Pages - 52
PRODUCTION TECHNOLOGY It was made of multi-layered blown glass. On the interior, an annealed white enamel painting can be seen. The exterior was decorated with the adaptation of a Habán pattern with enamel painting technique. The antecedent of the object was a ceramic wine jug made by the Habán, which was in the possession of the Bishopric of Pécs in 1893. We can find a publication about the original jug in the periodical Művészi Ipar from 1893. The article titled “Magyar boroskancsó a XVII. Századból” (Hungarian wine jug from the 17th century) was written by Péter Gerecze. From this article we can understand the years indicated on the surface of the glass jug. For example, the year 1689 is the date when the jug was made, while 1781 on the handle is the date when the vessel was first restored, when the lead dots were put on the surface of the ceramics. The date 1896 is strongly connected to the glass object itself. This is the date when the copy was made. It means that three different dates can be connected to the glass jug. The multi-layered glass making technology has the following phases. Two batches of differently coloured glass were taken on the blowpipe and they were blown together. The thickness of the layers depends on the quantity of the glass mass and the time of blowing. The thin yellow interior glass layer could not be produced with another technology. It is possible that the object was immersed several times into the colourless glass mass to obtain the thick outer layer. With this method, a wall thickness of about 3-4 mm could be reached, from which a sufficient amount of glass could be removed for the imitation of the wire mesh. The fields within the mesh were made with corrosion, which is the shaping of the glass surface with hydrogen fluoride. The surfaces meant to stay intact were covered with linseed oil or wax, then the whole object was dipped into a bath of hydrogen fluoride, sodium fluoride and water. The depth of corrosion depends on how long the object is left in the bath. The mixture of hydrogen fluoride and sulphuric acid corrodes the surfaces to a shiny lustre, while hydrogen fluoride leaves a matt surface. It can be seen on the mesh surface that corrosion was completed with polishing where the corroded fields did not give sharp enough contours. The last but one phase of ornamentation was to prepare the annealed enamel painting. Enamel is glass powder that melts on a low temperature, which is coloured with metal oxides and mixed with a matrix that helps painting. The matrix ensures the adhesion of the paint to the surface and it evaporates without trace during heating. To reach high enamel painting, the paint is applied on the surface in several layers and each layer is separately baked. The more layers are applied the more protruding the pattern seems. The last phase of ornamentation is when the mesh is decorated with metal. This can be made with annealing or with cold technique. The silvery metal decoration on the surface of the jug, regarding its adhesion to the glass, was burnt into the surface. EVALUATION OF THE CONDITION OF THE OBJECT, ANALYSIS OF THE RAW MATERIAL AND DESCRIPTION OF ITS CONDITION A jug was partly refitted, partly in fragments when I got it from the collection. The reason is that the old adhesives became aged, the refitted fragments fell apart, and new fractures appeared. The amount of the missing parts on the surface of the jug could not exactly be estimated, we had to wait until the jug was 52
