The book, now housed in the inner enclosure, is measured again, enclosure and all. (Some of the measurements may not have changed, but all three need to be measured this second time.) Working from these new length (L), width (W), and thickness (T) measurements, pieces of grey/white board are cut to the following dimensions:
Boards (2, each):
Length: L + 4mm
Width: W + 4mm
Spine:
Length: L + 4mm
Width: T
