Preparing Mosaics During the Courses
Mosaics are made out of glass, stone and fired ceramic material.
We order our smalti – a special type of glass specifically intended to be used in mosaics – from the Orsoni family in Venice (www.orsoni.com). There are also many other companies specialized in mosaic materials in Italy. In addition, gold and silver smalti are produced in Zelenograd near Moscow. Of course types of coloured glass other than smalti can be used in mosaic pieces as well.
In Finland, perhaps the best places to acquire stone are the leftover piles of factories that refine stone. Also self-gathered natural stones are good material for mosaics.
Easily acquirable material are different kinds of ceramic plaques, tiles, plates and sheets that can be picked up from e.g. hardware stores after cleaning day for free.
Also broken potware can be used as mosaic material – so if you’ve broken your favourite mug, don’t worry, you can still make use of it!
The materials are cut into pieces with a special hammer and anvil, whose hard edges are made of hard metal. These hammers and anvils can be ordered from shops specialized in mosaics in Italy and Zelenograd.
METHOD OF WORKING
We practice two different methods in making mosaics in the courses. You can either make your mosaic directly on wet cement, or on a wax surface made out of beeswax, paraffin, resin and turpentine.
MAKING A MOSAIC PIECE DIRECTLY ON CEMENT
The materials are cut into pieces of required shape and size. Usually mosaics are made of quadrangles, therefore they are commonly referred to as tesseras (lat. tessera = cube). The size of the tesseras varies from anything between pinhead-sized pieces to those matching the tip of your thumb, or even bigger depending on the size of the mosaic. The size of the tesseras can be consciously varied greatly also in one mosaic. Usually the smallest tesseras are used for faces and other important details whereas the background is usually constructed with larger ones. Varying the size of the tesseras is significant in that it brings liveliness and vividness to the piece.
Sketch on plastelline
The tesseras are pressed on a wet cement surface one by one. The method is very demanding for the artist. This type of working enables the artist to use various kinds of special effects in constructing the surface of the piece, which has a tremendous effect on the outcome. Unlike in floor mosaics, where the evenness of the surface is crucial, in wall mosaics the controlled unevenness of the surface allows the landing of light and shades contribute to making the piece vivid. In order to maximize light’s reflection on the piece the artist can place the tesseras on the cement so that their surfaces are slightly tilted towards each other. Also the shape of the cement surface and depth of the tesseras in it affect the way light reflects on the piece. For instance, the halo can be made slightly convex. The significance of these details cannot be emphasized enough - it is just these seemingly insignificant subtleties, along with the durability of the materials, that cause the churchgoer to be overwhelmed by the old Bysantic mosaics as he enters an otherwise dimly lit church, even though it has been centuries since the artist placed the very last tessera on the once wet cement.
In old churches, the mosaics have been constructed directly on the walls. Significant details have been constructed separately and then attached on the wall in its place. During the courses we have made only separate mosaics that can be moved around.
DIFFERENT STAGES OF MAKING A MOSAIC
A clear line sketch is drawn of the set piece. Once the sketch is ready, it is copied onto a large plastic transparency. The transparency is needed when the piece is transferred onto the cement. The transparency comes in handy also in ensuring that the different parts of the piece stay in place.
A tentative plan of the colouring of the mosaic is drawn with coloured pencils. This sketch is then used as a map when picking out suitable materials for the piece. Once the materials have been found, a suitable amount of each smalti and stone are cut for different parts of the mosaic. The sketch can be used as a testing surface onto which the tesseras can be placed so that there won’t be any unpleasant surprises when the cement is wet and the time to work on it is limited.
Sketch on plastelline
When the piece at hand is particularly demanding, it is a good idea to make another sketch on a wooden disc that has been covered with a thin layer of plastelline, a substance resembling plasticine. Plastelline will hold the tesseras in place during the planning of the piece before they are moved into their final place in cement.
Mosaic on cement
The final mosaic on cement
Temporary frames are attached to the e.g. chipboard base of the final work. The base and frames are treated with a glue mixture so that the wooden base won’t absorb any moisture from the wet cement as it would damage its solidity. A metal wire that is to be sunk into the cement in order to keep the cement and the base intact, is attached to the base. If the mosaic is intended to be kept outside, the wooden base is replaced with weather resistant veneer or a thin already dried cement base with a metal net.
A suitable amount of elastic mass is made out of water, glue, cement and sand. The mass is distributed little by little, approximately on an area the size of a palm at a time. The construction of the piece begins from the middle. If the central part of the piece consists of a face, the eyes are the first to be moved onto the cement. With the help of the line drawing made on the transparency, crucial lines are marked on the cement. This is when the moving of the tesseras from the sketch onto the cement begins. This phase of work is to be done quickly because the cement dries fast, in about 3 hours time. For this reason it is important that already when sketching the work, decisions about how dense the tesseras are placed and what type of lines they form, etc., are made. By delicate and premeditated placing of the tesseras, strong energy fields can be created even onto a monochromatic surface.
The finishing touch
Once the mosaic piece is finished, it is moisturized with water for several days until the cement has hardened. Then the surface is cleansed and the temporary frames can be replaced with e.g. ones made of stone. The ideal placement of the mosaic would be inside a niche in the wall so that the wall and the piece would form a unified surface, making the mosaic an intact part of the architecture of the location.
Mosaic on wax
Making a mosaic is anything but mechanic filling of different coloured areas with suitable tesseras. After having attended a basic course in mosaic art, one is likely to realize its challenges and will no longer wonder why the masterpieces in old churches are the work of not one, but several artists. The work was performed by a group of masters, each possessing expertise in a certain aspect of creating mosaic art: a drawer, a drawing enlargener, one specialized in mixing cement, tessera cutters, tessera placers for the more insignificant places, and finally, the real masters whose responsibility it was to create the face and other central sections. This is likely to bring comfort to beginners whose first mosaic does not quite match the vision they had gleaming in their mind in the beginning.
MOSAIC ON WAX
The wax is made out of beeswax, paraffin and turpentine. You can also use resin as a fixer. A wax surface stays workable for a long time – the wax will reach its final hardness in five years. The roots of miniature mosaics processed on wax lie in the Bysantic era. At that time, mosaics were prepared e.g. to be given as valuable gifts among the royalty.