In search of the color that seduced the World
Catherine E. McKinley 2011
So what does a book about Indigo have to do with symbols and signage?
A lot when the book discusses the role of clothes dyed with traditional motifs to state a message. The author an anthropologist became friends with a shop owner who made and sold clothes and dresses and who was willing to explain the meanings of the traditional patterns. Many of the symbols apparently were originally pictographs often expressing traditional proverbs or prayers for fortune.
When you're loooking at pretty patterns bear in mind many of tehm derive from ancient symbols.
... so and do read this excellent book even if it is about textile arts and not typography or lettering. There's also a look at how the introduction of modern fabric printing is effecting traditional methods.