Can someone help me understand proof grading? I see what lookes like a perfect coin then I see the

TheLiberator

So I saw a really pretty jefferson the other day and it looked flawless. What is it about a proof that makes it a 67, 68 or 69 and not a 70? I mean, I couldn't see ANYTHING wrong with it. What is the criteria for dropping a proof from "perfect" to "almost perfect?" What should I be looking for?

braddick

A whisp of a hairline or two will downgrade a Proof.

They're sometimes difficult to see, especially through a plastic slab.

kranky

Like braddick said, look for hairlines. You will probably need to rotate the coin around under a good light so you can see reflections from all angles. Hairlines can be invisible if you aren't looking at the right angle.

kieferscoins

Hairlines, tiny milk spot etc.

Cameron Kiefer

eagle7

Die polish will cause PCGS to hold a grade lower, when there is no sign of anything else on the coin. I know that diepolish is as struck, but it does not matter. Even a few very small die polish lines visible only with a 10x loupe and a bright tensor light will get the coin downgraded at PCGS. Hairlines are different, and are even worse of a problem. Hairlines will usually limit a grade to pr65 or less, even if there are only a few. JMHO.

Wolf359

Die polish will cause PCGS to hold a grade lower, when there is no sign of anything else on the coin

I didn't know that. Thank you.

Russ

Thread on proof grading.

Russ, NCNE

greghansen

Russ, Thank you for the thread link on proof grading. I had managed to miss that first time around. Proof grading is an area that I've always had to rely upon the 3rd party services much more than I would like to. Nice to have the obvervations from a submittors point of view.

TheLiberator

Thanks so much everybody! Also, thanks to Russ for that thread! Your two different pics of the same coin were AMAZING! So what causes hairlines? HAIR?!!!!!!

Small scrapes in the die I would imagine...correct?

XpipedreamR

No, hairlines are light scratches on the coin itself.

XpipedreamR

Small scrapes on the die would be raised on the coin, like die polish lines. Hairlines go into the coin.

lordmarcovan

Hairlines are caused by a variety of contacts. Even dust can cause hairlines to the delicate surfaces of a proof coin (after all, some dust particles can be abrasive like sand, just on a smaller scale).

When one gets up into the lofty end of the grading scale, with those 68-69-70 coins, the differences are not always apparent to the unaided or untrained eye. The tiniest mark can make a difference.

Speaking personally, I will be the first to admit that I can't tell a 69 from a 70 (if a true 70 really exists), and I'm outside my range of confidence anywhere over 67 or so.

When I sell raw coins in my booth at an antique mall, I personally will not grade anything over "65+". To me, it has to be in reputable plastic for me to sell it as a supergrade coin. If it's raw, then 65 will be the highest claim I make, even if I feel a TPG service would give it a 66 or higher. (I mostly sell older coins in circulated grades, anyway.)

BowTieCoins

Thanks russ, very helpful

keets

while hairlines can certainly be a problem they aren't the only thing to consider. strike plays an important role in the grade, though it's not as much of a factor on modern proofs as it is on pre-1970 proofs.

al h.

Myqqy

It's also important to note that if you're looking at slabbed proofs to get a better grasp on proof grading, be sure not to pay too much attention to proofs graded by third world slab companies. Many (or most) companies outside of pcgs, ngc, and anacs seemingly have little idea how to grade proofs, and you'll see a lot of 68's, 69's, and 70's that are in reality much more impaired....