How to protect silk-screen from scratching (toner-transfer)?

Interesting combination! And what are concentrations of HCl and peroxide? Pitting on large copper area? Are you using a laminator? Sorry to bother!

HCL industrial grade..usually colored RED, Hydrogen Peroxide 20% volume colored BLUE. 1 part HCL to 2 parts Hydrogen Peroxide..this will strip a 4"x6" blank PCB in 3 minutes flat!

Pitting occurs and depend on the quality of toner transfer..usually on large plane but manage to fix it with Sharpie pens industrial colored RED item #: 13801

Thanks for the useful information!

BTW I'm using ordinary cloths iron...