I like it a lot! A couple ideas:

1) For the alphanumeric full-length private key in the square, if we use a fixed width font and rely on the fact that (as I understand it) WIFs always have 51 characters, then we can always show the key in a tidy pretty square like this:



With the 7 "firstbits" larger for easier checking, and then exactly 4 rows of 11 characters.

2) Regarding bleed/perforation offsets, your design should do great even with a 5-horizontal perforation template -- except for the darker "ripples" in the upper left corner (which would ripple onto the bottom of the bills above it).


I'm coming into this project pretty late so I might be confused on this matter, but I thought the plan was to have diecut perfs so you can just fold and tear -- no exacto knifes needed.