Gaslight style is the result of the inspiration and competition between the jobbing letterpress printer and the lithographer. Bookplate and re-usable ornamentation had been around for centuries with the earliest examples dating back to the early 15th century, but it wasn’t until the 18th century that printers were able to produce ornate printing in large quantity. In the early 19th century there was a sudden demand for the use of color from advertisers and publishers, both jobbing printers and lithographers met that demand with constant experimentation in composition, style and process. As styles matured in artistic (and jobbing) printing, lithography became even more detailed and exuberant, showcasing their skill at transforming the page into an articulate expression of space using forms that folded, curled, framed, and cast shadow across the boundary of the page.
Gaslight was first established as a style in the 1870’s the style was said to have derived from the play of gas-lit streetlamps on building signage of the time (thus the drop shadows and faux three dimensional letter forms) It was also characterized by bright colors, stripe and ribbon work, ornate framing, and use of the whole page. Below I have provided a couple of examples as well as a pintrest album with a huge image bank of gaslight graphics.
As with any style, it becomes the basis for inspiration for later generations of artists, printers, and designers. Gaslight style has, like many other styles, found its place as inspiration in modern art and graphics. I have seen many examples over the past couple of years that emulate or take inspiration from Gaslight, from chalkboard lettering artists to the popular “hipster designs” you can see the characteristic three dimensional type, the ribbon and drop shadow, folded faux paper and even abstractly demonstrating light and it’s relationship with physical lettering.
GASLIGHT GALLERY – Pintrest gallery with tons of examples of Gaslight style, it’s predicessor and ancestor styles
 – http://en.wikipedia.org/wiki/Bookplate#Early_examples
 – David Jury – Graphic Design Before Graphic Designers 2012 – pg.189