[Leica] IMG: Painting Question

[jhnichols at lighttube.net (Jim Nichols)]

I know there are a lot of photographers out there that are knowledgeable of 
the art world.  I have a question about the painting depicted in the 
attached link.

This painting was given to my Mother many years ago by an elderly aunt who 
lived in central Kentucky.  I have always assumed that it was painted by a 
local artist, but had no luck tracing the source.  When it came into my 
hands about twenty years ago, the frame was in need of refinishing, so I 
disassembled the painting to work on the frame.  What I discovered was that 
the canvas was wrapped around and glued to a sheet of glass.  At some point, 
the glass had been severely cracked.  I carefully assembled all of the glass 
pieces and taped up the glass to hold it all together.

My question is this:  Is this a common practice, backing up canvas with 
glass?  I have never encountered it before.

The painting is shown here:
http://gallery.leica-users.org/v/OldNick/Painting.jpg.html

Comments and answers welcomed.

Jim Nichols
Tullahoma, TN USA