* Iron(III) chloride / Perchlorure de fer '''Corrosive!'''
or
* HCl + H2O2 / Acide chlorydrique + Peroxyde d'Hydrogène (eau oxygénée) => [http://hackaday.com/2012/04/30/etching-your-own-boards-really-really-fast/ HCl+H2O2 method on Hackaday]
== Safety ==