Anyway This one's inspired by the Lawn Fawn dies but made on the scoringboard.
I also made it to fit both the imperial and metric paper and envelopes and also so you only have one little strip of waste :-D.
You could make the box 4 inches high as that would also fit the envelopes, but at 3.5inches you can get 3 boxes out of one sheet, either metric or imperial.
Only difference is the little tab you use to glue the box shut, it's wider on the imperial version. You could cut your paper down to 8 1/4, but there's really no need to and i think the wider take holds wider tape, so it might actually be stronger.
I used the metric in my video.
you cut the paper down to 31/2" strips, you'll get 3 out of the sheet bit a bit left over, in the metric that bit is big enough to make the little dividers/ tabs, but you can use scraps for that of course.
On the short side you score at 1 3/4"only
On the long side you score at: 2", 4",6" and 8".
Cut away the little tab on one side and then apply red sticky tape and fold the card shut.
To make the tabs/dividers I cut the left over strips into 3"length and scored them at 1/2"and 2 1/" and put red tape on the little side flaps too.
I didn't decorate the box on the outside, but you can of course, each panel is 2"x1 3.4".
I use acetate or packaging to mount my little images, so the strips are invisible, particularly handy with planets, or birds and this jumping narwhal, but cardstock will also work of course.