How much does a date stamp written in ink affect the grade

[DCman]

I have a few FF's with both, dates stamped and some have it hand-written in ink, on the cover. My question is, Does a date written in ink have more of a negative effect on the grade, vs a date that has been stamped on. I was under the impression that CGC did not downgrade books for dates that were stamped. How do they treat hand-written dates with ink. I know they downgrade books that have random markings written in ink.

Below is an example of FF 58 with a 10-20 on top. It is a sweet book, but I am not sure how CGC will treat it. Any thoughts would be appreciated.

 

[Sid]

I don't think they have much effect on books below 9.6. Larson copies are prime example of this.

[FFB]

If they're small and unobtrusive, you can have them all the way up to MT 9.9 per the Overstreet Grading Guide (second edition).

[jkc313]

Even Mile High's have marks on covers