Looks good to me especially that he is known for signing side ways alot of times plus that how he signs his J's as well.
Yes I did
I don't think it's authentic. Not just because it was sold by that seller, which I figured it was, but because it doesn't look authentic at all. I also came across another one that seller sold and it looks like he/she did a similar quick guided signature, using almost the same placement with the Ja in Jack. In addition to that, Jack Nicholson does not sign his first name like that. The Nicholson part of the signature doesn't even look right. On that other example I've posted, it appears he even screwed up when quickly trying to sign his last name.
I also noticed a number of other fake signed items offered by that seller.
Are you the seller of the Nicholson in question?
why would i be the seller if i just commented to this guy saying just ask for a refund if you dont want this item anymore?
B/c thats exactly something the seller would say trying to make his business look legitimate. (assuming the item is fake)