Today I continued hashing out specifications on the pressboard needed to construct the board. It turns out that their pressboard comes in 26" x 38" sheets. This needs to be cut down to make a quad-fold board approximately 14" x 20". Adding to the complications is the fact the packaging cover art cannot exceed 13" x 19", the largest paper I currently have access to for printing. Allowing for the edges of the box and some wrap-around, the top of the box will be 4.5" smaller and the bottom box will be 0.25" smaller still. This allows for a maximum folded board size of 8" x 14". A folded size of 7" x 10" fits well into this space, but causes an unacceptable amount of scrap when cut from the sheet. Therefore, the board will have to be 6.25" x 9.25" when folded.
My contact at the paper company is also working on a quote for the necessary amount of Kivar6, a backing material. This will (I hope) take the board from mediocre to semi-professional. I also finished the box design work and am now working on the box bottom (I took a nice photo today). Things are progressing steadily forward.