Why are rectangular labels the most popular sticker shape?

Rectangular labels are the most popular sticker shape for two reasons. Firstly, most labels are designed to fit primary product packaging like bottles, jars, cartons and so on. Most primary packaging is roughly rectangular and this determines the shape of the label. Secondly, rectangular labels have a lot of space to include loads of information to within millimeters of the cut contour, so the reasons make very good business sense. Rectangular is a simple sticker shape that can pack a lot of information or graphics.