Here is a quick diagram with measurements for the box I made 2 posts ago. I have drawn it up fairly quickly so please excuse if there are any errors. Perhaps I should put this E&OE 🙂 The top is cut from one sheet of 30 x 30 cm card as is the bottom. I made it this size to suit Australian size cards with envelopes with room for stamps or pens at the side.
Hope this helps. Always happy to give measurements if I haven’t given the project away and so can still measure it up. Just ask if it still isn’t clear.
Bye for now,