Gelatinous 3D Painting

I made a joke once that to draw something in 3D, you need 3D paper.  The comedic value in this line comes from the fact that paper is not 3D (anything drawn on it is essentially 2D, you don't want to start that argument with me).  The comedic value in the previous line is that I explained the obvious nature of the joke.

Anyways, I have an idea on how to paint or draw in three dimensions, and it involves clear gelatin, a syringe, and ink.  The basic concept is that ink can be loaded into the syringe, then injected into the exact location of 3D space where you want to make a mark.  Over time, with lots of injections, you can make a shape, similar to those glass souvenirs in gift shops.  The potential of this new medium of art is incredible.  With some refinement, as well as good artistry, gelatinous 3D painting could become a legitimate art form.

I have provided a quick sketch of what I imagine the process to look like:

As a final note, think of how weird it would be to check out of a store with these items.  Gelatin, syringes, ink, no big deal.