I would guess probably something like 91mm x 55mm at 600dpi.
zoldergoose,
Wed 4 Feb 2009, 21:53,
archived)
I think that's business card sizeI reckon they would be tart-card size like the ones normally found in phone boxes - just google to see them in situ.
(
beaubodor blogless,
Wed 4 Feb 2009, 22:01,
archived)