Tiles are easily damaged
There are instances of mosaics made of broken tiles, which are in fact very beautiful. Anyone who has visited Barcelona, will know the visionary splendour of the works of Antoni Gaudí – and also many who haven’t.
The catalan architect has left an indelible footprint in art history; in his houses of the unexpected shapes, in the sculptures of the Parc Güell, coated in mosaics of shining colours.
Colours which keep on shining since a hundred years, in the Mediterranean sun; and millions of visitors have been bewitched by the artist’s works.
What visitors don’t see however, or fail to appreciate, is how easily the tiles are damaged. And when they do stand a damage, it is painfully evident.
Ceramic tiles used in buildings as coatings, are made of a mixture of natural and synthetic materials; the mixture is mostly made of clay or ceramic earth, with colour and enamel applied on the outside for the purpose of giving the tile a polished finishing, which will make it resistant to water, soap, detergents etc.
The raw material, soft and pliable, is turned in a hard and resistant end product by keeping it at a specific temperature for a given time, in special ovens.
Two alternative procedures are used: either cooking the raw material, then applying colours and enamel, and cooking again to consolidate the enamel; or cooking once only, with the enamel applied on the raw material.
Two different procedures, each with its advantages and disadvantages, which we will not discuss here.
However we all know that by cooking, the raw material is turned from a greyish dough to a solid, hard reddish-brown mass – the “terra cotta” colour. There is one sole exception to this, consisting of materials “coloured in the mass”.
In their daily household use, tiles are placed next to one another to form a surface that is optically uniform, and it’s the same whether it is solid coloured material, or decorated in any way.
It is also common experience, that a shock, maybe from a falling object, can chip off part of the coloured enamelled coating: out pops the reddish terra cotta colour.
More often than not, the problem is quickly fixed: the damaged tiles are still available on the market, or a forward-looking landlord has kept a couple of boxes as a reserve “just in case”. A couple of hours of a layer, and the damage disappears (truth be told, sometimes the difference in colour in the grout-filled gaps can be seen; or you can tell a slight difference in the colour nuances of the decoration, especially when the manufacturer used non-sunlight-fast dyes).
Now, something like this is much harder to remediate in a mosaic. And you can tell when you visit Barcelona: millions of visitors admired the Parc Güell since it was opened to the public in 1926, but they left traces of their visits. Gaudí’s visions are still beautifully there; but the damages are also there, and you can tell.