Slab Toning

jjroll

Which slabs cause toning? Which slabs prevent toning?

Just curious

Shamika

I believe all of the modern ones are supposed to protect against toning.

However, only NGC and PCGS guarantees against any grade reducing toning while in one of their slabs.

coinguy1

jjroll,

It's not the slabs themselves, so much as it is how / where the coins are stored. Even the best holders do not always prevent coins from toning, spotting, changing, etc., if they are stored in a hot and / or humid environment.

Once a chemical reaction has begun on the surface of a coin, it does not necessarily stop, just because a coin is slabbed. Also, even slabs which are touted as air tight, do not prevent gasses from being absorbed into those holders.

From what I have read, I believe that the Intercept Shield products are the best protection available. For purposes of full disclosure, I was, at one time, a part owner of one of their distributorships.

Conder101

There is some concern that the label in early NGC slabs (NGC 5 and earlier) can contribute to the toning of silver coins in the holders. Many otherwise white silver coins seem to develop toned areason the obverse at the top of the hole where it is closest to the label.

MadMonk

What about Metal Safe VCI? That's what I've been relying on?

jbsteven

PCI slabs do tone silver eagles