How To Describe Light Creasing On A Mint Stamp, Not Showing When Dipped?

I'll try to describe better--
Usually on larger commemoratives, and if the stamp is lightly hinged or never hinged, there may be some dents, creases, that I don't think are really creases.

Sometimes not visible on the outside of the stamp, never going to the edge of a stamp, always internal. I've tried to describe these in terms of:
light internal creasing, not visible in watermark fluid
light gum bends, not visible in watermark fluid, etc.

I also think that in most cases, these would disappear completely if the stamp was soaked. I don't think that the stamp is not sound.

When I've bought a stamp, I've seen these many times over the years, and haven't ever complained. When I've sold one, I haven't had anyone complain either.

I know that everyone has seen this, and hope that I've described the issue correctly. Is there a proper way to describe these "dents, internal creases, bends"?

Thanks, Ray

Gum bends was the first thing I thought of.

Sounds like gum bends, which is normal for a lot of issues. It certainly sticks out when looking at the back of an otherwise pristine stamp. For those into grading, depending how visible the bend is, it could be noted on the certificate and possibly affect the final grade.

Thanks!
I thought that this was probably "gum bends" but wanted to see if there were other opinions out there.

Thanks for the response, Ray

To me, a crease 'breaks' the paper fibers partially and is visible in watermark fluid. Something that doesn't break the paper fibers, and is not visible in fluid, I would call a 'bend'. If I can determine that it is caused by gum shrinking or bending, I would call it a gum bend. If the bend is 'native' to the paper, I would call it a paper bend. In either case, I would indicate that none of the paper fibers are broken, and this is not visible in fluid.

Frankly, expect returns, nonetheless. No matter how honest and accurate you try to be, there will always be some that have a different opinion.

Same, I will call that a "gum bend" or "gum crease" in my listings. With "light", "small", "large" etc modifiers as needed.

And re returns, very true. I have a "no reason required" refund/return policy but customers (rightly) tell when in the few cases they aren't happy with a stamp. Some can be a little odd - I recently had a customer return a MNH** stamp due to the "gum condition". The gum looked great to me, but I sent a pretty much identical replacement - customer happy with this one so problem solved :)