Blasting/sandblasting technology
By using a compressed-air sandblaster gun, the sandblasting material is blasted onto the item, and depending on the material, small parts are removed. The item becomes clean or the surface material becomes compacted.
Different blasting materials produce different results.
The sandblast roughens the surface of the glass, thus it becomes matte. The degree of roughness, the result on the surface, depends on the grain size, the type of the blasting material, the blasting pressure, the distance to the item, the duration of the blasting process, and the angle of impact. We obtain our matte surfaces by treating them with very fine blasting material in order to achieve a satin-like surface.
By covering the glass surface with special foils, the uncovered parts get matte, while the rest remains clear.
When gradually removing the cover foils, multi-stage effects, respectively different opacity levels can be achieved. The glass surface can be carved deeply with a special foil that resists the sandblast particularly well. Even holes (for outlets, wash basins and so on) can be achieved, which is very suitable for complicated holes, cutouts and recesses and in cases when a CNC machine or a water jet cutter cannot be used or are too costly.
Stencil foils are either produced manually, based on old handcrafting techniques, or by using a computer: here again, the foils, which are manufactured by a cutting plotter, have to be taken and transferred onto the glass by hand. In the case of patterns that are too small for foils and the plotter, foils produced by photo technique are applied, which allows letterings and griddings in the range of millimeters.
In earlier days, stamped sheet metal stencils were used for patterns, which were transferred onto hand-made sized paper (paper soaked in pearl glue). When exposed to heat and humidity, the sized paper became sticky. It was then transferred onto the glass surface, and cut out by hand. Nowadays, high-quality foils with different specifications replace the old technique of sized paper designs.
Old patterns and postscripts are still designed and cut out by hand, or after a complex digitization process produced by a computerized cutting plotter. However, the transfer of the patterns is still carried out manually.
