The bottom of the 1-2-3 bottom boxes is divided into three folds or flaps. When these flaps are joined together the box takes its constructed position. These interlocked flaps give a completely secure and closed bottom tray, which enables the box to hold the weight of the product that is to be packaged inside. This mechanism is just like the one we follow while solving a jigsaw puzzle where the pieces get locked into each other and form any shaper or picture. They are weaker than the auto-locked bottom but are stronger than those tuck end boxes. These flaps provide full support to the top flap so it gets into its place properly.