Newton’s rings ???
 

Purchased a W554 5” x 7” card in an SGC slab and it has what looks kind of like newton’s rings, but they are stationary and don’t look oily. They almost look more like dirt. The card inside the sleeve can move a bit, but the dirt/newton’s rings are stationary in the slab even when pressure is applied. So do some newton’s rings just not move?

Also, this is second thing I’ve bought (the first was a photo in a PSA slab) with what I think are obvious Newton’s Rings, but neither of the auction houses mentioned them in the descriptions.

So I guess it is customary to not disclose the newton’s rings in the description?

The Newton’s rings in the PSA slab for the picture change shape when pressure is applied and look more like oil/moisture. Maybe the SGC is just more rigid than the PSA slab, so the newton’s rings in the SGC slab don’t change with pressure?

So the card moves in the sleeve but the sleeve stays stationary? If so, maybe the rings are from the sleeve's contact with the plastic of the slab?

I think you are right, and even though the card is moving around, the sleeve the card is in is not, and so the Newton's rings caused by the light shining through both the slab and the sleeve are stationary.

I guess with the relatively rare size that the W554 is, SGC doesn't have standard slabs that will hold the card in place without a sleeve. The card was graded in Feb. 2022, so I think it is unlikely I'd be able to avoid the Newton's rings with a reholder.