Last week I made a whole bunch of own stencils from overhead film. I find them perfect for use with the gelli arts plate. The prints from the stencils are giving a different structure than from the gel plate. This way you get beautiful effects and you can make more prints from one session.
I used some embossed card stock for texturing and got a beautiful scrap for further use.
One of my most favorite “paint” for gel printing is acrylic medium. I use glossy and matte and I love both of them. It is perfect to make a pastel last print from left over paint on the plate. You can liquidify with just putting 3-4 drops of medium onto the plate, then using the brayer to spread it over the plate.
This is one big advantage of the natural gelatine plate. It is wet, the Gelli Arts plate is dry. But with acrylic medium even the last traces are going off and make wonderful last prints.
Have fun trying this!