How pizza boxes are made

A pizza box ships flat and folds without any glue, thanks to a cutting die that creases and slices in one stroke.

stations: 5
things upstream: 55
raw sources: 18
steps from the ground: 8

The short version

Corrugated board, a rippled paper sheet glued between flat layers, is printed and then fed to a die that cuts the outline, creases the folds and punches vent slots in one stroke. The flat blanks are stacked and shipped to the pizzeria, where staff fold the walls and flaps into a box.

Ripple the middle sheet

Paper passes between two heated, interlocking rolls that press it into waves called flutes. Pizza boxes often use fine E flutes, with a pitch of 1.0 to 1.8 millimeters.

E flute pitch 1.0 to 1.8 mm

Goes in
Paper
Glue on the flat liners

Starch adhesive goes on the flute tips, and a flat paper liner is pressed onto each side under heat. A knife then cuts the moving board into sheets.

Goes in
Paper Adhesive
Print the outside

Flexible plates print the brand and instructions on the outer liner, one plate for each color.

Goes in
Ink
Cut, crease and slot

A steel-rule die presses down on each sheet, cutting the outline, creasing the fold lines and punching vent slots in the same motion. Robert Gair found the cut-and-crease trick by accident in 1890. The slots let steam out so the crust stays crisp.
Stack the flat blanks

Blanks are counted, stacked flat and strapped, which saves a great deal of truck space. Staff fold them into boxes at the shop, with no glue needed.

End of the linePizza box

Worth repeating

Neapolitan pizza bakers once sent pizzas to street sellers in round metal containers called stufe, which means ovens.
The first patent for a corrugated pizza box, from 1963, already had flat blanks, glue-free folding and vent slots.
The little plastic stand in the middle of some pizzas is called a pizza saver, and it stops the lid from touching the cheese.