The Roman Rules
Almost unique in any art form Roman mosaics had a set of Rules used by every mosaicist. Throughout the Roman Empire from Britannia through the Mediterranean, North Africa and into the Middle East you can see these rules in their mosaics. A Roman mosaic floor was intended to be seen in its entirety there should be no one point of focus. The use of triangles in a mosaic implies a direction, put any together and they will create a very sharp line. In a mosaic this creates a point of focus, a part of a mosaic which when you notice it will draw your eye to it every time you step into the room.
The other rules used allow flow, continuity and depth of field. If you don’t know the rules the chances are you won’t see them, once you know them and any are missing you’ll spot them straight away. How did they disseminate this very specific training across the Empire? We don’t know, very little information has survived about the craftsmen themselves and as they worked with their hands they were considered manual labourers therefore not worthy of great accolades or status in the way that we think of artists today.
The main rule, Borderline is, in figural mosaics the setting of a line of tesserae (tiles) all the way around the outside of the figure. If you look at the background the white tesserae are set in horizontal lines and where they meet any lines of the figure on a diagonal you need to cut triangles to fill the space. If this line of triangles were against the figure itself it would create a sharp line for part of the figure which can disrupt the overall effect. If there were a line of tesserae inside the figure on the horizontal you would get triangles cut here also which would disrupt it even more.
In geometric mosaic this rule is also used, essentially where colours change you must avoid having a line of triangles. Look at any geometric mosaic and you will see the borderlines in use.
Some of the rules are very specific to Roman mosaics, the others are more general ones used to create continuity of effect.
It is for this reason that you can criticize a Roman mosaic; modern work cannot be criticized as you do not need to follow any rules. If you go to Ravenna in Italy to the Scuola Arte del Mosaici everyone begins with a piece for piece copy of a Roman mosaic, regardless of their previous experience.
The advantage for contemporary artists in learning the rules is that when you know them you know how to break them.
©Lawrence Payne 2010