Just etch through it. Since the fine layer isn't enough to block the etchant, it undercuts the individual grains of toner and removes the copper anyway.
Or are you getting a solid coating on the bare copper?
You can use a little bit of air or tapping to knock off excess toner, although that removes ANY toner, I find it doesn't remove much from the inked areas. I just let it sit for a while so the toner in the ink has a chance to really settle in, then I tap it upside down and sometimes blow on it a bit with canned air. Once in a while I have to manually clear areas between pads that are too close to each other by scraping off the toner with a sharp blade or probe.
Another issue is humidity... and static... there may be a fine balance between the two.
Please let us know how it goes and what you find works for you?
--
James.
--- In Homebrew_PCBs@yahoogroups.com, "g3umt" <g3umt@...> wrote:
>
> Hi,
> I'm fairly new to the group and finding your post's very useful. I have purchased and modified an Epson S21 printer and have been experimenting with Ink/Toner hybrid method.
> The info available seems to say dust the wet ink with toner which I find works and produces a good tough coat of resist. I can't however stop a fine layer of toner sticking to the bare copper!
> Anybody using this method? if so, how do you apply the toner to stop this problem please.
>
> Regards,
> Brian
>