Finding this incredibly frustrating! I am trying to find a Postal Box that is at most 2.1cm in height with flexible dimensions of 24cm length and 17cm width (slightly bigger than a DVD box.) This can be flexible to suit existing sizes. Now I can find the boxes, I can even find the boxes with a single colour on the outside, but I need the inside of the box printed in a single colour. I have experimented with turning the box inside out but it doesn't seal properly. Can anyone suggest someone who can provide these boxes or a printer who could print on the flat pack boxes prior to assembly?