Minnie Minoso....documenting time and place
 

how important is time and place in autograph authentication?

Not sure exactly what you're asking. I make sure the style is representative of the time period in question IF the item can definitively be dated. If it is an early signature on a later piece, red flags obviously. Ball point in the 30's, ditto. But any earlier item can be signed later, so that's not so helpful.

The basic question is how important when authenticating a signature is date and time? This one was obtained in person at this event named. Was wondering if authenticaters use this kind of info when looking at a signature.

Absolutely! The previous poster's point was that exemplars of a person's signature from different time periods, instrument (type of pen) used to sign, etc. all are helpful when considering authenticity.

Absolutely. Every day.

I review quite a few Neil Armstrong signatures. I always date the item if possible. This is because his signature changed significantly over time. Certain items he stopped signing at certain times. This all creates more opportunities for forgers to make mistakes.

I can't tell you how many times I've seen an 80s or 90s style signature on an item he stopped signing in the early 70s. Or a 70s style signature on an item that dates to 1993. Truth be told, the signature is almost always identifiable as a fake anyway, but it's nice to have the extra nail for the coffin. :D