The dry photographic plate, the forerunner to film, was invented in the 1870's and replaced the "wet" plate which needed to be made at the photographic site and had a short shelf life. The dry plate could be made at a central factory and shipped to photographers and offered a shelf life of 9 months or so.
Hammer was an early leader in the production of dry plates, before Kodak took the dominant position in the industry.
This two-sided wooden trade sign, in the form of a hammer, dates from the early 20th Century and was used as an over0counter display where dry plates were sold. It is 24 inches long.
The Hammer dry Plate name is in black with gold leaf detailing (on both sides) on a green and gold painted surface.
Condition is good with some surface scuffing and some loss to the lettering.