Ghostsigns are the old advertisments that were painted directly onto the brick on the sides of buildings. They are gradually fading away, although occasionally a new one is revealed when a modern poster site is removed for maintenance. Clapham is one of the best areas of London to see them.
Click on the photos to see them larger.
Edit – 26/04/2017: I recently noticed two ghostsigns I hadn’t seen before on Lavender Hill. I’ve added them to the gallery. One is easily readable, but I can’t make out anything at all on the last one, although you can see that once there were six separate panels.
Also, the TV, Audio, Video Repair sign has been painted over and is gone for good.