The cobblestone mosaic in Liguria is called "rissëu". The known origin of these mosaics in Liguria dates back to around the 14th and 15th centuries: this is the period in which this art began to spread and establish itself in the region. To date, Liguria is certainly the Italian region with the highest number of pebble mosaics. People from iguria, and the Genoese ones in particular, have been navigators for centuries (the city of Genoa was in fact one of the 4 ancient Italian Maritime Republics, together with Pisa, Amalfi and Venice) and surely, the Genoese sailors, in addition to establishing exchanges and commercial relations with the peoples of the Mediterranean, also imported the noble art of pebble mosaic into their homeland. Liguria, which is a mountain range overlooking the sea, is geologically rich and therefore has guaranteed over time the abundance and easy availability of stone materials, naturally present on the beaches and on the banks of its streams.
It is also for this reason that hundreds of square meters of pebble mosaics can still be admired, scattered almost everywhere, from east to west of the region. Initially these mosaics decorated the churchyards, the spaces in front of and close to religious buildings, churches, cloisters and convents. These mosaics with a strong symbolic charge, containing dense weaves of signs, full of metaphorical and even metaphysical meanings, served therefore as a place of passage for human consciousness, from the external world to the sphere of the sacred one. They were a channel for the churchgoers who entered the worship place.
After the first Hellenic-Roman stylistic influence, with the beginning of the 17th century a Baroque taste prevails in the Ligurian risseu artisanship, but the Hispanic Moorish influences are also remarkable, thus creating a Ligurian style, which provided a wide choice of models to imitate, from the floral intertwining to more rigorous geometric designs, compositions of animals and sea monsters and symbolic representations. Little space has been devoted to the representation of the human figure, which can only be observed in rare examples. The black / white bichromatism in this technique has evolved over time by introducing other colors into the pebble mosaics: we therefore find gray, green and red pebbles, depending on the area of collection of the materials. From around the 18h century the Genoese aristocracy also began to use this type of decorative style, to embellish villas and private gardens. The use in the Italian garden is also important from a stylistic point of view, with the creation of grotesques and nymphaeums covered with very appreciable mosaics. In addition to the pebbles, the technique was enriched with the use of other materials, such as majolica, shells, and glass pastes.
Finally, in the last two centuries, the Ligurian "rissëu" has found its popular soul, spreading in public squares, in gardens, or on the waterfront of the Ligurian villages and cities, where pebbles are easily found. It is common now , in fact, to find mosaics inserted in the architecture of the urban fabric where natural building materials are still dominant. Unfortunately, this artistic heritage risks being lost over time, thanks to the lack of sensitivity by the institutions and, above all, of funds for restoration of the mosaics. Furthermore, the authors, or "masters" of this manual skill, have left only a few oral traditions that have never turned into a form of codified instructions. Since the past the knowledge has been transmitted only to direct collaborators and what has remained as today's knowledge of this art is based on the techniques collected by researchers from the last elderly craftsmen who still operate in the sector.
Only recently the risseu techniques have been taken back into consideration by young local craftmen with the aim of not losing this precious tradition, possibly re-introducing this type of decoration to modern yards, building and gardens, along with giving the opportunity to properly restore the old works.
The realization of the “risseu” floors, today as in the past, is the result of a close collaboration between the client and the artist. The client provides information about the desired subject; the decorator executes the drawing to verify the applicant's interpretation and wishes; the agreed sketch is then adapted to the available space, choosing the representation scale most suited to highlighting the drawing and preparing the decoration project that is made on paper, in real scale.
There are also specific ways and times for a patient and systematic collection of the stones; the search usually starts at dawn, preferably after a violent storm. In these conditions the colors of the pebbles are highlighted by the grazing light and the shades of color are better enhanced.
The choice and selection of the pebbles is of fundamental importance for the successful completion of the work. The technique of implementation obviously has evolved over the centuries, but without substantial variations.
First, the laying is made on the place where the mosaic must take place, digging, drawing, consolidating the soil and laying the bed usually formed by a layer of wet and compressed sand.
Over the years the technique has been refined by replacing the old base mix with other more consistent mixtures such as that with quicklime and pozzolan or with lime and powdered porcelain, a sort of mortar that, soft at first, hardens around the pebbles, to give greater cohesion.
The Rissëu is also a handwork ment for being trampled, therefore subjected to wear and tear, its construction as simple as it may seem in the tools and materials, requires very precise construction methods. The laying process, in order to be lasting, must be done by expert hands: only a very narrowly positioning of the pebbles will create the right force movement responding to the law of the opposite thrust of two bodies in the texture of the mosaic, increasing its resistance and compactness .
But the most demanding part of the work is the one dedicated to the chromatic selection of the pebbles collected to make up the mosaic. The material collected in the area, sometimes, affects the color combinations and the size of the pebbles which can be, for the artist, a source of variations on the basic theme.
These technical needs, dictated by random unexpected events, if well resolved, confer flair and value to the work itself, making it unique in its kind.
Despite their considerable historical and artistic value, Ligurian cobblestones have not, over time, been the object of sufficient protection: they were often approximately and improperly renovated instead, by replacing the sand bed, traditional support of the Ligurian risseu, only with ordinary cement mortar.
To perform a proper restoration of an old risseu, the experience and sensitivity of a master craftsman is a must, as he knows how to combine mortars, lime and cements together in the right proportion.
For those who are passionate about this craft, it is possible to move from theory to practice: the Musivarius Laboratory, located in via Loria in Genoa, in addition to laying mosaic coverings and floors, also organizes courses that allow interested students to learn the pebble mosaic technique or the Roman marble mosaic technique with the traditional method of cutting the tesserae by hand with the help of a hammer and a kni