||Corbels have been a standard architectural component for thousands of years. The ancient Greeks used corbels for structural purposes in their public buildings, as did the architects of the Roman Empire.
Load bearing corbels are generally designed in triangular fashion: one flat surface fastened to a vertical structure and one horizontal surface to support the arch or crossbeam or whatever structural piece lay overhead. The third side of the triangle, facing outward, was the area that was decorated with carvings.
A pilaster traditional corbel can also be a load
bearing component, but is principally designed for decorative purposes.
Pilaster corbels generally do not follow the triangular structural
template, designed with much less protrusion from the vertical
a standard corbel might have five or six inches of extension on
its top, horizontal side a pilaster corbel will have perhaps two
or three inches of protrusion. A pilaster traditional corbel
is basically a long and slender decorative piece, with sufficient
extension in the upper portion to give the piece dimension, or
to support a narrow crossing structure above it.