Plaster Low-relief Carvings

So I kind of came upon this project by accident. I was pouring some plaster into molds of world masks. I had some left over, and seeing how quick-setting plaster of Paris tends to be, and how non-wasteful art teachers tend to be, I decided to see what sort of print would turn out if I set up some plaster in a foam plate that had a design drawn in it.
A quick drawing, the remainder of the liquid plaster, and sure enough... the outline comes out very nicely (I was skeptical seeing how shallow the pen lines are, even at the deepest you can make them without creating a hole in the plate). On the first design, I covered the design with metallic paint and called it done. Mind you, this is probably nothing new to anyone else... but I was pleased with my discovery nonetheless. :D
But wait! Dry plaster scrapes away pretty well with clay tools and even popsicle sticks... so we should scrape away the background and add texture before adding metallic paint, right? Yes. So it's our experimental project in Visual Arts (5-8). Here's the carving with a layer scraped away (without detailed outlining at this point):

 Like I said, I used leftover plaster mix for this so it wasn't very thick, but you can take that into consideration when pouring it, depending on how much contrast you'll want between the positive and negative space. Since mine was pretty thin (and especially thin along the edges), some of the edges broke off.
We are detailing around the subject, and using sand paper to smooth down the scraped away areas, but the texture will still be contrasted against the smooth, untouched area inside of the main subject. The next step is to add in any additional texture, smooth away any extra lines or mistakes, and paint with metallic paint to finish it off. Be looking for posts of finished artworks! I'm so excited to see how all of these turn out.