Unusual backing?

Hello,
I recently looked at the back of this, and see the print is on what looks like 1/4" thick plaster. Everything you see, all the layers held in by the nails, are a solid piece. It looked unusual to me. Was this a common way to mount prints? I'm trying to picture this being the intended way to mount, or where it was previously that it had to be cut out. Just curious!
Thank you.

 

I think that somebody used a thin piece of plasterboard for backing. I imagine it was just something they had handy at the time. The image itself looks faded, has lost most of its red. I think you'll find the original painting was by Watteau.

 

That makes sense. I would have thought that cutting it would be too awkward to even attempt! And, thanks so much. I didn't know the artist. It's definitely faded. My mother-in-law had it for a long time.

 

No Watteau but a contemporary. 'The Music Lesson' by Nicolas Lancret. (French 1690 - 1743.) And, yes, it is faded. An internet search will bring up similars like this one. Typically these are 1910ish to 1930ish and now valued more for the frame than the artwork.

Debora