As always comiket paper bags has various style, also I’ve read that you will purchase an amount of 2000 yen for you to have your own Comiket Paper Bag to carry your goods around.
With the manufacturers, and game developers Navel, Windmill and Feng I think they have oversized paper bags now.
I’m just envious of people who visits Comike, I wish I’m there, and wanting to get a ticket now. ^^;
[Source]
Just moé 
Navel bags are huge because they always have huge items like towels etc. Comiket is something you have to go at least once just to experience it. I’ve been to two already but I’m not surprised by the things I see anymore.
@Adun
Wow, really? Just too bad for me, I’ll plan this coming summer on getting to comiket, I’d just hard a have time on my needs especially money u_u