I went to the DaVinci exhibit today. I had a 9:30 time. You line up separately from other ticketholders into 2 lines that have dark blue carpet runners saying Léonardo DaVinci right in front of the center of the pyramid. They had the 9A group in a separate slot and they were allowed in at 9A. We were allowed in to the Pyramid at about 9:28. I was chatting with the guy next to me who is seeing the exhibition for each of the 5 days he is here. He said yesterday (opening day) the security folks let the whole line in about 15 minutes early. It depends on the particular security team you have as to whether they will let you in early. The ones today were very strict. They did shoo us to the center doors where we then filed in with the other ticketholders for the security screen. Who knows how this will be after the exhibition is going for a while. Once you are thru the security you take the escalators down the the lobby area under the Pyramid with all other ticketholders. You then head to the Sully wing and you’ll see the sign for the Da Vinci exhibition.
I agree with Janet. Based on both the Vermeer exhibit last year and this one I’d go directly to the exhibition area. This was NOT as crowded as the day I did Vermeer but that may change. There was no line once I got to the special exhibition area and they were just scanning the tickets and letting everyone through.
By the way, I did go to Mona Lisa afterward mostly just to see how the refurbished room looked. I managed to work my way around from the Denon wing via the Sully wing to the Richelieu wing with just one entry scan at that point.
Be sure to keep your tickets in a sheet protector. The lady behind me when I went back in through the Sully entrance had had her ticket folded in her back pocket and some of the bar had rubbed off. She said she had had trouble getting into the Da Vinci exhibit and the lady scanning at the Sully entrance was not going to let her in but relented when she looked at the ticket. One of the others in their group was not admitted to the Da Vinci exhibit and was told to go reprint it. (?? Like how are you going to do that?) I looked at both tickets and they looked like mine, printed at home so my sense was they were not scamming.