What is a Ghost-Sign? It's not Sign from a Ghost!

A Ghost Sign on a Baltimore Building. Credit: Steve C. 

Here's a bit of Trivia that I just learned about from my friend Steve C. in Baltimore. He found out faded signs painted on the walls of old buildings are called "Ghost Signs." Here's an old Coca-Cola sign that Steve photographed on a building in Baltimore. Not a sign from a ghost, but a ghost sign!  

Here's the history of them according to Wikipedia: 
Source: http://en.wikipedia.org/wiki/Ghost_sign
    Ghost signs are found across the world with the United States, the United Kingdom, France and Canada having many surviving examples.^[1] Ghost signs are also called fading ads^[2] and brickads.^[3] In many cases these are advertisements painted on brick that remained over time.^[4] Old painted advertisements are occasionally discovered upon demolition of later-built adjoining structures. Throughout rural areas, old barn advertisements continue to promote defunct brands and quaint roadside attractions.
Many ghost signs from the 1890s to 1960s are still visible.^[4] Such signs were most commonly used in the decades before the Great Depression.^[5]



The painters of the signs were called "wall dogs".^[6] As signage advertising formats changed, less durable signs appeared in the later 20th century, and ghost signs from that era are less common.
Ghost signs were originally painted with oil based house paints. The paint that has survived the test of time most likely contains lead which keeps it strongly adhered to the masonry surface. Ghost signs were often preserved through reprinting the entire sign since the colors often fade over time. When ownership changed, a new sign would be painted over the old one.

Conservators today are being asked to preserve the original signs rather than painting over them.

References:

1. Ghost Signs - A Waymarking.com Category
2. see Fading Ad Gallery
3. see Ghost Signs
4. Ghost signs: Old slogans never die in Butte..., The Montana Standard (Butte, Montana). 9 August 2001. Accessed 6 September 2007.
5. Joseph Berger. "Fading Memories". New York Times. November 5, 2005. Retrieved on October 5, 2009. Genovese, Peter (March 30, 2012), Ghost signs: Jersey's commercial history is written large in faded paint on city buildings, The Star-Ledger, retrieved 2012-03-30