What is greyboard?

This is the key thing to understand about rigid boxes, and it explains most of what is different about them. A folding carton is one printed blank, creased and folded. A rigid box is two separate things — a greyboard structure and a printed paper wrap — made independently and then brought together by hand.

That construction is what gives a rigid box its character. It does not fold flat, it holds its shape under pressure, and it has the weight in the hand that people associate with expensive products. It is also why the wrap can be almost any material, including papers and textures that could never survive being creased and run through a folder-gluer.

The consequences are cost and time. Every box is assembled individually, the wrap has to be aligned by hand on each one, and the boxes ship already erected, so they occupy far more space in transit than flat blanks. Lead times are substantially longer than for folding cartons and are not comparable — that is worth planning for when you set a launch date, rather than discovering it during quoting.

Greyboard caliper is what defines the wall thickness and therefore the feel. Heavier board reads as more premium and pushes up both cost and the wrap dimensions.