Secondary processing or "Cold" processing includes all the techniques executed without melting glass in the oven.
The "conterie" are glass beads rounded or sharp edges, obtained by processing "a lume" dissecting perforated tubes pulled into the furnace for about ten meters. The glass rod unperforated is softened by the heat of the fire escaping from a torch, subsequently is wound around a metallic tube which gives the pearl the desired shape and finally decorated with the use of polychromatic glass. The conterie are different from those worked in the past that were called margarite. Their work was introduced in Murano in the thirteenth century by Cristoforo Briani and Domenico Miotti. By their numerous pupils born flourishing industry still active.
Enamel Decoration "Decorazione a Smalto"
The technique of glass decorated with enamel involves the use of colored compounds obtained with powders of opaque low-melting glass and finely ground transparent,
applied with a brush on the surface of the glass to realize a decoration which can assume abstract silhouettes, vegetable or figurative.
The decorated object is subsequently subjected to a thermal cycle which does not exceed 500 ° C, in this way the glass applied with a brush,
softening, it adheres permanently to the glass surface of the support.
This type of technique has Eastern origin and was introduced in Venice in the last decade of the thirteenth century with a large fortune in the Renaissance.
With "millefiori" is defined as a perforated or non-perforated barrel which has inside several concentric glass layers of various color and form, usually in flower or star.
The processing first involving the use of open molds that imprint from time to time the different shapes depending on each of different color layer and then the circulation of the barrel along tens of meters.
A special type of millefiori cane is the rosette, which dates from the fifteenth century, characterized by motifs in star white glass, red and blue, in alternate layers.
The millefiori cane is usually cut into sections called murrine. The segments obtained from a perforated barrel, after being bevelled, can become the pearls.
While the non-perforated sections may be put together and fused to the heat of the oven so as to prepare cooked or bowls and if fused to the bottom of a small mass of crystal hemispherical,
of pressacarte or papier-presses.
The grinding is a technique, it remained unchanged for many years, which allows to dig the glass and is carried out in several stages.
The first phase involves the use of a very crude wheel comprising silicon carbide grain "80", the second stage consists in adjusting the incision previously performed with a wheel,
always in silicon carbide, but more fine-grained "220", the third stage acting with the moltaura and smoothing the incision through the use of a wheel natural sandstone.
In the fourth and last step the object is passed back with a cork wheel impregnated by a mixture consisting of pumice stone and water with the purpose of polishing the incision.
A work done we proceed to clean and make the bright object with a wet rag wheel of cerium oxide and water.
The origins date back to the Renaissance of Venetian mirror. The mirror processing is based on a glass plate, with a part coated with aluminum or silver,
which produces an image by reflection of the figures which appear in front of it. Only in the late twelfth century and the beginning of the thirteenth there was the spread of glass mirrors with a metallic coating and,
with the Renaissance, Venice and Nuremberg became the renowned centers for the production of these items.
In the sixteenth century the most popular way to make a mirrored glass surface consisted in applying a thin reflective metal layer, often a mercury and tin alloy (amalgam).
Later in 1835 Justus von Liebig discovered the chemical with silver glass coating process that gave rise to the production techniques of today's mirrors.
The procedure is to spray, under vacuum, a thin layer of aluminum or silver on the lower part of the glass sheet and wait for the reaction to electrolysis.
The metal layer deposited on the opposite side to the reflective is covered by a paint for protective purposes.
It is an ancient technique, which also includes the mosaic glass. of different color glass sections are juxtaposed on a ceramic fiber plate and melted in an electric furnace so as to obtain a multicolored vitreous mosaic or said fabric murrina glass. They are arranged on the plate or fragments of different colored glass beads that blend with the basic vitreous support. The operation can be repeated several times by overlapping the colors and creating a three-dimensional decoration.
The murrino glass is a technique among the oldest, it is a second processing which consists of a vitreous composite plate by welding with heat the tiles of different color glass cut from polychrome rods,
the plate is subsequently molded with the use of a mold in fireclay and can also be further modified by taking the form of a vase.