Here’s the sort of thing that got Large Format Printing off the ground- signs for a company meeting. You see them all over the place at every conference, and we do a ton of them. They direct people to the right place, announce what is happening in the room, get groups of people together.
Typically these are made of paper mounted to foam core board, and are stood on an easel outside of meeting rooms. In this picture, they are in a 22×28 signs holder, and we usually use 50 point board for that, since the slot on the top of these sign holders is a little too small for foam core board.
We also do a lot of vinyl banners for events and meetings, so you can come to one place and get all your meeting signage done.