The reason for my question is that I developed a method to increase the density of HP tones without changing the resolution. In brief, I paint over the entire transparency with black marker for white boards. When it is dry, I just rub over it with a soft tissue like Kleenex. The black marker fills the small voids in the traces and pours, but is removed from the clear areas. Recently, I found that it does not work with Brother toner. Apparently the solvent in the dry erase marker dissolves the Brother toner, but not he HP toner. Under a good magnifying lens, you can see the difference. HP toner has a granular appearance. Brother is splotches. I have not tried it on Samsung toner. If you have one of the dry erase markers, you can try it.
John