Marble and precious stone
From ancient quarries and the remotest extents of the Empire, Romans imported marble, mother-of-pearl, lapis lazuli, malachite and turquoise, cornelian and jasper along with inexhaustible supplies of travertine from Tivoli for their floors and wall art.
Smalti Glass
From wood fired furnaces on the Island of Murano, Venice and the Vatican factory of Papal Rome, ancient glass craftsmen supplied the coloured and gold glass used throughout the Paleo-Christian and Byzantine world used to produce wall and vault mosaics of supernatural brilliance and effect.
Over time, the ancient glass craftsmen dwindled and today there are less than “a handful” in Italy who still fashion the rare and genuine coloured and gold glass smalti in the way of their ancestors.
Mosaic Tools
Since antiquity, the most satisfying tools for accurate cutting stone and marble were a mosaic hammer and hardie. These same tools are still in use today and remain the preference of Hand-Mosaics.
Separate mosaic hammer and hardie for glass smalti and marble are used by Hand-Mosaics. When cutting gold smalti using both tools avoids wasting too much material when cutting.
Double Reverse method The Ravenna Method
The mosaic is first made on a temporary bed of lime putty (hydrated lime in a powder form, to which water is added) is used. It is an air-setting lime not hydraulic lime!). Some workshops use ordinary clay, although Michael prefers to work with original Lime Putty.
Before laying the tesserae, Michael creates a tracing of the cartoon and then reverses it onto to the lime bed. When the tracing paper is lifted, the cartoon outline is left behind on the lime. To keep the bed soft it is regularly sprayed with water and covered with a plastic sheet at the end of each day to protect against the humidity in the workshop.
The lime stays soft for weeks and even months, is spread on a particular type of board made of straw and cement, which absorbs water and slows down the drying process of the lime putty binder.
In order to lift the mosaic from its temporary base to the permanent binder an open-weave fabric (normally several layers of cheese cloth) is glued on to the surface of the mosaic. The water-soluble glue used today has exactly the same basic ingredients as that used by ancient mosaic artists in Ravenna – rabbit skin and bone! Today the glue comes in pellets, is exceptionally strong and dissolves in water easily and is very economical, any unused glue can be used again and again.
A flour paste (the kind of glue used by bookbinders) can also be used - but it will not keep for such long periods - or even any type of water-soluble glue (even white glue) can be used.
Michael prefers the Double Reverse method as this enables him to use tried and tested ancient styles and create a more exact mosaic before finally placing it into its permanent cement binder.
Direct method
Under this method, Michael places tesserae, section by section, directly into a bed generally made of cement. With this method, the tracing is performed section by section.The direct method is also used to make mosaics sticking tesserae onto a fibre glass net.

If there is a need to make a small mosaic panel (maximum size approx. 70 cm x 50 cm) - that is then installed somewhere else (wall, floor, Apse). Each tesserae is attached onto the net using a thin layer of tile cement, another thin layer will be spread directly onto the surface of the wall, floor and so on. Then, when complete the mosaic "panel" is simply pressed into the bed of binder
Indirect method

In this method, tesserae are arranged face down on a strong paper sheet using water-soluble glue, which bears the inverted design.

When the design is completely covered it can turned up and then pressed into a prepared setting bed of permanent binder and, when set, the paper is dampened and removed.
This method does not tolerate change, once it is set there is little chance of correction, however, it is a quick method but leaves a rather flat and smooth surface, aspects which are not present in classical pieces but widely used in production studios and commercial mosaics (especially for table-tops).