Interest in older tattoo flash and designs from the early 20th century has revived lately in the tattoo community. These classic or retro tattoo designs can be found both faithfully recreated or updated with a postmodern sensibility.
There's no rigid set of guidelines for what constitutes a "classic" tattoo design, but most often it's taken from images and the styles of coloring that were utilized in the first half of the 20th century. Many younger tattooists today are growing up and working in environments without a heavy social stigma attached to their skin art. After a huge surge in popularity of Japanese-style tattooing, many American tattoo artists are now taking a look at the history of tattooing in the US for inspiration.
Tattoo design elements such as the rose, the dagger and banner, and the Rock of Ages all fall under the umbrella of classic. A lot of the images that were popular with sailors during World War II are also staples of classic flash, such as the blue bird or the pinup girl.
Tattoo colors in the early 20th century were black, green, red, yellow, with limited use of blue and brown and not much else. Shading was also less complex and designs relied more on stronger lines and snappier outlines to look good. The style of tattooing was most often stand-alone designs placed next to each other without any background or unifying theme, an aspect that still typifies most American-style tattooing.
A good number of the flash designs created by Sailor Jerry in the 40s and 50s has been adapted for greeting cards, coffee mugs and household items which has helped fuel the popularity of his work years after his passing. The resurgence of interest in swing dancing has also helped along classic tattoo designs. To go with their 40s fashions and music, many of the younger people embracing this culture are also getting 1940-style tattoos to complement their look. In homage to the W.W.II shortage on nylon pantyhose, when women drew stocking seams up the backs of their legs, modern-day swing girls have the stocking seams permanently tattooed up the backs of their legs.
Interestingly, one location where interest in classic tattoo designs is raging is Japan. The social taboos there are much stronger around tattooing, with its ties to the Yakuza history, but slowly that too changing. Influenced by American movies and music, Japanese young people are pursing the practice of getting American-style tattoos, not only getting singular, stand-alone designs, but American images as well.
If you'd like to learn more on this topic, you might like
Spiritual Tattoo: A Cultural History of Tattooing, Piercing, Scarification, Branding, and Implants
by John A. Rush
The Tattoo History Source Book
by Steve Gilbert