Hi Gabriele - in addition to the info that Tom provided, the IPC-1601A specification has some information on "Silver Saver" paper which is used for the purpose you are investigating. Dave Hillman Rockwell Collins [log in to unmask] On Tue, Jan 23, 2018 at 6:04 PM, SALA GABRIELE <[log in to unmask]> wrote: > Hello > > > > Please, could someone there explain me the difference , if there is any, > between Sulfur Free Paper and Acid Free Paper ? > > > > I am investigating about paper sheets interposed between PCB (ENIG and > ImAg > finisch) when piled up for packaging and shipping. > > > > Many thanks > > > > Gabriele > > > > --- > Questa e-mail รจ stata controllata per individuare virus con Avast > antivirus. > https://www.avast.com/antivirus >