This is my version of a 'Happy Retirement' card. Criteria was classy and can fit about 70 signatures. I've used the flag book concept. You're looking at a 12 by 6 inches blue silver vietnamese silk bound book with light blue satin ribbon tie. I put in a floating label so it could be personalised to the recipient.
Flip the pages like a regular book with ample space to write the greetings in. Added in a bit of detailing at the corners to tie the insides and covers, isn't it pretty?
And you can stretch the whole thing out to 3 feet long and the pages stand to attention like flags!