[types of cardboard]

These examples use 0.03 paperboard
"30 pt" = "0.030 inch thick"
it is too thick for origami, but still pliable enough to bend and crease by hand

[example source]
Utrecht Chipboard - Kraft, 29" x 46" x 0.031"

use clear packing tape for closures

given an open-top box with dimensions H x W x D

start with a piece of paperboard (H + W/2) x (2W + 2D + 1) inches
where W <= D



cut along the dotted lines
fold along the solid lines - drag the flat of a metal ruler down the creases to sharpen them
fold everything inward
tape the 1" vertical tab to the opposite box edge - tape outside and inside
fold the bottom flaps closed - tape outside and inside

start with the Box instructions

if the box is too small to get tape to the bottom inside
then use a wheel fold and just tape on the bottom outside

make the final dimensions of the lid 1/8" bigger in each direction
for a lid that is 1" high, the paperboard dimensions are (W + 2 1/8) x (D + 2 1/8) inches



fold the edges down
then fold the little tabs inward and tape the corners closed

to contain a sheaf of paper and keep it straight





set W >= D (this will provide a more sturdy bottom)

there are extra cuts here, to make the bottom flaps attached to the W sides short enough to close

for the bottom flaps
- there will be long and thin ones attached to the thin D sides
- and there will be wide and short ones attached to the wide W sides
- fold the long/thin ones in first and tape them together
- then fold the wide/short ones and tape them from the outside
tape the 1" vertical flap closed last
- tape it to the outside of the sheath so that it won't stick out on the inside
- get a little tape on this inside edge to keep it from catching the paper

once the sheath is all together
- draw a straight line across the front a bit below the top edge
- then draw a straight line from that to each side corner
- use scissors to cut this angled section away