The lines of Art Deco are crisp and clear, either literal lines or as borders between colors.
Lines that relate should be of the same weight. Lines should be weighted relative to their scale, so lines associated with a large scale should be weighted heavier, while lines associated with a smaller scale should be weighted less.
Line weighting tells the viewer's eye which layer is which. Line weighting sorts all the confusing elements into sensical patterns.
Not all lines are literal lines. Some lines are implied lines. If you take four squares and arrange them in a square, the space between those squares will create the illusion of lines. There's no line there, but the brain puts a line there anyway. Implied lines are just as important to Art Deco as literal lines.
Literal lines imply shapes. A cross hatch of lines creates a field of diamonds. Which is real? Are the diamonds the design element or the line? The answer is that it's subjective, and Art Deco uses the subjective view of the viewer to an abusive degree.
The lines of Art Deco greatly depend on the purpose of the piece. A gate, with its many bars, requires many parallel lines. A floor does not. Even though those lines may create a busy appearance, they're needed, even if they don't look Art Deco, so necessity creates challenges.
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.