Rules for Art Nouveau

I like figuring out algorithmic rules for particular genre's of art and architecture. 

Art Nouveau - This was a style that arose as a reaction to Academic Art.  If you wish to understand why Art Nouveau seems to break so many rules (while still providing evidence of being fully aware of them) have a look at how rigorously the rules were emphasised in Academic Art.  Think of Academic Art as a "Street Art" style that arose from Academy trained artists wanting to express themselves differently but not being able to forget all the rules they had already learned.

So  my "rules" for Art Nouveau are:

2.5 dimensions.  This means that the image is composed of discreet "layers" which do not obey the same coherent rules of persective or foreshortening.  Each Layer can include these elements but they are not "simulating" depth.  Z order is essential but needs to be "played" with to create a wholeistic composition.

Establish borders and framing then break it.  One of the essential elements in this style is the breaking of the frame.  This creates the entertaining "flow" between the layers and binds the whole image together.

Use frames and borders to "punch through" and combine layers.  This technique also creates links betwen the layers and creates relationships.  This compensates for the lack of relationships that would otherwise be created by the rules of depth and helps with the Mise-en-scene of the content elements.

Contrast between geometric repetition and organic repetition.  These should be similar scale to help re-inforce the juxtaposition of the two different styles.  For example the conrtast between a repeating geomtric motif and a group of  flowers or butterflies.

Similarity rather than symetry.  Elements are often "similar" in that they occupy symetrical areas on the composition but are not "mirror" images.  This plays with the concept of geomtric symetry, showing that the artist is aware of the rules but has chosen to be "playful" with them.

Dynamic lines work and outlines. The hand inked style of the line work and the heavy outline styles are characteristic of the materials and the media that the early work was build with.  This has come to be part of the "signature" of the graphic design work.  (Obviously not a factor in the Architectural works)

Curves.  The convention of never quite having a straight line is one of those rule-of-thumb that the artists "play" with.  I think its the contrast between the curves and the lines that make for the playful nature while still being "constrained".  The curves tend to be flowing lines and "spline" type curves rather than crazy scribble type lines.  They are very dynamic and directed.

Content.  The style draws in and often contrasts geomtric motifs and styalised nature. Figures and objects are often posed together with the figures being displayed in "static" poses with dynamic elements such as hair and drapes shown blowing styalistically in the breeze.

Shading and textures.  The use of flat colour to create obviously simple shading and "hand painted" style shading contrasts with true shaded gradients creates an interesting juxtaposition of textures.  This can be a subtle effect.  Generally each layer has its own "style" of shading which is consistent through the layer.  Soft washes and out of focus forms are often layered in the background.