Hi David, Normal mechanisms of Ag tarnishing are: Diffusion of copper (do you have a brrier layer of Ni/Pd??) Presence of sulphides in the atmosphere. Organic stuff in packaging materials. Best Regards, Ken McGowan. ----- Original Message ----- From: David To: [log in to unmask] Sent: Monday, April 09, 2001 1:53 AM Subject: [TN] Immersion silver boards tarnish Has anyone ever exeprienced immersion silver MSP boards tarnishing, turned yellow after stored in ambient condition?