When you think about cheerful patterns, the polka dot is one ... haven't been singing about yellow bikinis with the circular design, the dots have had a major influence on culture.

That was before I read Jude Stewart's Patternalia: An Unconventional History of Polka Dots, Stripes, Plaid, Camouflage and Other Graphic Patterns ($25, Bloomsbury), which was published this month.