At Kaps Finishing Ltd we can provide wiro bound documents in sizes A3, A4, US Letter, A5, 1/3 A4 and 210mm x 210mm square.
You can also have a custom size wiro bound product, the maximum size we can produce at Kaps Finishing is A3 portrait or landscape as above and the minimum size is A7.
With regards to sizes of wire Kaps Finishing use, the maximum is one inch in diameter and the minimum is 5mm, for the one inch wire the book block can be no thicker than 23mm.