In terms of cards I believe it to mean when a trimmer takes too much of an edge and not enough off the corners. This leaves the card with the bat ears shown above.
Did you every buy 1988 Score BB when they first came out and they had all that extra fuzzy stuff on the corners because the cutting machine sucked. That is bat ears.
Sometimes when a card is trimmed, the two corners on the edge that were trimmed flare up, like a bat ear.
I highly suggest taking a modern day Topps common (like 1989 Topps, for example), trying it a few times yourself so that you know what to look for. Use an exacto knife.
Marc
I am actively buying MIKE SCHMIDT gem mint baseball cards. Also looking for any 19th century cabinets of Philadephia Nationals. Please PM with additional details.
Comments
In terms of cards I believe it to mean when a trimmer takes too much of an edge and not enough off the corners. This leaves the card with the bat ears shown above.
I highly suggest taking a modern day Topps common (like 1989 Topps, for example), trying it a few times yourself so that you know what to look for. Use an exacto knife.
Marc
A quick class on card trimming w/ bat-ear reference