Developing Chemical Symbols on Acrylic Pours

During my research, I decided I'd do some experiments involving chemical symbols and incoporate them into my acrylic pouring and watermarbling experiments. I started by using black and white pens to draw the symbols on top of the acrylic pours. I found that outlining the symbols in white made it stand out against the colours of the background.
The first experiment I did was using the below piece as a background.

This was on wood which I'd painted red, before doing an acrylic pour using yellow grey and red acrylic. I used black and white pens to draw differnt chemical symbols. On this piece, is THC, Meth, Nicotine, Domapine and an Alcohol. After just drawing them in white I found they were lost in the chasoitc background so I decided to highlight sections and go over some with white, which I felt helped the symbols stand out more effectivley.

This was the final outcome after I did another layer of acrylic pour over the top. I used PVA glue on its own in the pour as I know it dries clear, so where the glue is poured will act as a window to the layer below and show the chemical symbols. I feel I should of used lighter tones as the dark greys blend together from both laters and the overall chemical structures are lost. 

I then attempted the same technique again, but used just yellow and pva glue for the top later, as I felt it would be a greater contrast in colours showing through more of the chemicals on the background.

This piece I feel is the strongest yet, as the symbols are still visible but not lost and there are distinctive layers. I think the chemicals can look more structured if I chose to print them insted, as they still look very raw and I feel printing them might give a greater contrast between the harsh lines of chemicals and the fluidity of the acrylic.

I find the top layer almost hides how rough the structures look, so I created one more sample but didn't add a top layer, so the symbols stand out more. I created the marks by not including oil in the pour, just flow enhancer. I then placed a piece of scrap paper over the fresh pour before peeling it off in an upward diagonal motion. This leaves a trail as the paper is lifted and creates these very light and whispy lines in the acrylic. I find the symbols look too raw and rough when draw by hand, so I'll print some on acetate and see how I can add them to my work .