What facinated me the first time I printed with Gelatine was that the gelatine enabled a fine, smooth structure (and this is possible from a hand pulled print!). I actually started with oil paints (water soluble) and was spoilt by the fantastic results. The problem is that oil paints are not so readily available, are expensive and therefore one doesn't experiment as much. I was determined to find something that I could buy around the corner and didn't cost too much. So I tried acrylics - which are good, but don't give the same fine structure. Then I moved to acrylics and wallpaper glue which was better, then I tried acrylics and dishwashing soap which also worked well. Today I tried dishwashing soap and pigments (normal pigments that one buys at the hardware store to add to PVA to paint walls) and I was so excited to find that I am getting the result that I was looking for. Fine, smooth structures with no "suction marks" as with the acrylics.
So now the realy work begins - now I need to use my experience to make real Art. What real art is can be debated, but I am sure it is more than willy-nilly pulling prints off a gelatine slab.