Yes, it can be done with the entire mouth being covered by the card. No Gaps. I'll use a smaller glass when I shoot my live performance video.
That would be great, I'll be looking forward to it whenever you get a chance to record and upload it.
I am also working on a coin through card case effect that was released a couple years ago. You have someone select a card and sign their name across the face which is then placed into the center of the deck. You cleanly show the glass with the mouth being completely covered by the deck, and then show 3 coins. With a quick slap, you hear *CLINK* and the first coin has gone through the deck and landed in the glass, which can then be examined.
Next you show that you have 2 coins, and with the same move, *CLINK* the second coin has magically traveled through the deck and ends up in the glass. You show that everything is still normal and place the 2 coins in the glass and cover it with the deck, and now you show the final coin, and after slapping the deck, you hear nothing. The coin has vanished, you show that there are still two coins in the glass, the next part is really wicked. You remove the cards from the case, and spread them across the table, and directly in the center of the deck, there is a card with what looks like a coin laying on top of it. Upon closer inspection, the coin is actually imbedded IN the card, which is turned over to reveal to be the signed card by spectator.
After that, everything can be examined, it's truly a wicked routine, and I'll be sure to post a video of me performing it this weekend.