Art Deco strives to do two things:
1. Destroy boundaries through use of lines and shapes.
2. Create boundaries through the use of lines and shapes.
A building, by definition, is a series of boundaries. You are stuck with them. As an architect, you want to break up some shapes inside, around, and through boundaries, and to do that, you need to define your own lines and shapes that draw the eye more than the natural boundaries of the building. As such, you can't design Art Deco without being accounting for boundaries because accounting for boundaries is a pillar of Art Deco.
Boundaries are manipulated using line weight and shapes.
Line weights heavier than any boundary will dominate the eye, thus becoming the primary characteristic. Your eye notices the bold stuff first. Your eye will organize everything on this scale before it considers organizing on any other scale. With this method, the viewer is introduced to the shape that you, the designer, want them to see, rather than the static shape that has to be there.
Boundaries can be destroyed either figuratively or literally.
In the case of rounded corners, the boundaries are literally removed. Art Deco frequently uses rounded corners to soften the shape of sharp angles, especially in buildings.
Boundaries can be extended. You can add to the physical shape, which serves the same purpose as rounded corners. you add on to break up.
Boundaries are figuratively destroyed when a bolder shape intersects a less bold shape. The two objects intersect, breaking up the shape of the object.
Another way to break up and object is to draw it differently. By putting in shapes and angles inside a shape you want to break up, you change the impact of that shape. Most frequently, curves alter lines and lines alter curves.
Remember that in Art Deco, you can't see all the lines and curves. Some are invisible. You may see that shape that results from a line or a curve without seeing the line or curve itself. In this case, you completely destroy an object but leave its impact.
Return to: Art Deco 101
Douglas Milewski is a fantasy writer who liked drafting class too much. In his recent artistic struggles to produce art deco for his own covers, he found no internet sites dedicated to the technical underpinnings of the art. Seeing a niche that needed filling, he has documented his hard learned experiences. He doesn't claim that he's right, and would very much appreciate it if someone more competent would save him from his own folly.