The gel bed is fine, but I'll show you some of issues we've been facing.
First, we get a sheet of carbon paper, then a sheet of gloss paper (gloss photography paper for an inkjet printer is optimal for this, but there are plenty of other glossy papers around). The gloss side of the paper is face down, in contact with the "inked" side of the carbon paper. In this case I've got a sheet of tracing paper as well.
I'll use a map of a familiar country to work through this process. I've pencilled it onto the tracing paper, the. Then next step is to get the image onto the glossy side of the paper using the carbon paper. For this, I use a stylus (a ball-point pen that has run out of ink would work just as well). Tracing the map, I get an image on the glossy side of the paper where it has been compressed against the carbon paper.