91% isopropyl and Bounty paper towels work fine for cleaning the copper after sanding it. Don't use cheap tissue that sheds. Also for double sided boards I drill the registration pin holes before sanding so the sanding removes burrs. Here is an example of a double sided board done with this method, note the 'copper' silk screen values etc. https://hackaday.io/project/25741/gallery#86a5661397dafe0b3c4ffcc3110e0288
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Re: Vintage PCB toner transfer problems ios-propyl wipe
2017-07-10 by AncelB