Reply To: How do I create large billboard sized InDesign documents?

You should really liaise with the printers for everything.

You only normally have to do it to quarter the size, or sometimes 1/10th the size.

Billboard resolution is around 40 ppi.

So if you do it to 1/4 the size make sure your ppi is 160 ppi so that at full size it's 40.

But again, check with your printers to what scale you should design to and what ppi to aim for.