Message:

<p>[QUOTE=&quot;-jeffB, post: 1715353, member: 27832&quot;]If that were true, how would &quot;album toning&quot; spread across the face of a coin, when only the edge of the coin contacts the paper?</p><p><br /></p><p>You&#039;re not <i>entirely</i> wrong -- toning will happen a lot faster where the coin is actually in contact with paper or cardboard. But the sulfur present in paper and cardboard gets released over time as a <i>gas</i>, either hydrogen sulfide or sulfur dioxide. Either can cause toning. That toning is vastly accelerated by moisture, heat, and probably light, but it can happen slowly even in dry, cool, dark conditions.[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in