use: For cutting: kitchen shears and a craft knife/NT cutter/X-acto knife/box-cutter. Corrugated cardboard gets its strength from the flutes between its liners. They dictate how you can manipulate the cardboard itself, but when used correctly, can add a lot of strength to a structure. First, and most obviously, avoid including pre-existent creases, unless you want them for a particular reason. These are weakened areas in the cardboard. Second, make fold, bend and roll lines parallel to the flutes. Let's come back to that in a minute. First, let's work with regular cereal-box cardboard: Suppose you want to join two little pieces at an angle, like the walls of a tiny box. First, you'd need to make a little overlapping tab for applying some adhesive. Sorta like a seam allowance. For it to bend, you'd need to score a fold line. This just means you scratch a line with something thin that will weaken the surface but not cut through it. Like the back of a knife blade. Then you can make a neat fold. You'd put some glue on the underside of the folded tab and attach it to another piece. You could score and fold in any orientation because cereal box cardboard has no corrugation. With corrugated cardboard, you'd have to pay attention to how the flutes are lined up. Folding/Bending: You'd want your fold line to be parallel to the flutes- this way you only distort one or two flutes in the fold and the rest of the