The Rules in Roman Mosaics


The Rules in Roman Mosaics - What are they?

Why is there always a line of the white tesserae (tiles) around figures?

(It's not as you might think to make them stand out, it's actually so they don't stand out)

The reason that you can criticize a Roman mosaic and not a Modern art mosaic is that the Romans set the patterns in their mosaics following a distinct set of rules. Sometimes this is referred to as Andamento or is classified as an ‘Opus’ (work) such an Opus Vermiticulum or Opus Classicum. For the sake of simplicity I use the term ‘The Rules’ when I refer to the way in which the Roman craftsmen worked.

It does seem that the Roman mosaicists used these Rules to ensure that no one area of a mosaic stood out as a result of the patterns in which the tesserae were laid out. They wanted everything to flow, for the viewer to see the patterns and not the tesserae. The floors may have had  highly artistic figural works for example which form the centre of a floor but you don’t want any one section of the floor to draw in your eye. The Rules applied to every part of the mosaic, there may have been some differences in the quality of the work but these Rules were seen in all the mosaic.

Also, with stone you only have a limited palette of colours, you tend to work using 'shades' as opposed to very distinct colours. So you need to set them in such a way as to make the best use of what you do have.

There are eight Rules which can be seen in Roman mosaics but you also need to learn the exceptions to them and also how they can be affected due to the standard of an individual mosaicists work.

These 8 Rules are:

 Borderline - Convergence - Keystone - Brickwall - Line end - Size - Spacing - Channelling.

Learn the Rules; apply them in your work and most importantly every time you see an original Roman mosaic look to find them.

Validating the Rules - Why isn’t there more about them in museums?

I always say to my students, ‘Don’t just believe what I say about the Rules, go look at the mosaics and see for yourself’ The caveat being that they need to be aware of the difference in standards but they are always there you just need to know where to look. I was originally taught these Rules by Luciana Notturni who runs the Studio Arte del Mosaico (Mosaic Art School) in Ravenna, Italy and is a master restorer. She explained to me that curators and other academics do not get involved in the process of creating these mosaics so they do not know about the process of actually setting the tesserae.

A common interpretation of the Borderline is that it is to make the figures stand out. Read the Borderline Rule and you will see that it is so they don’t stand out.