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