12 is divided into 4x3 (8x4) x (12x3) x18, which is the capacity.

But the outer carton has its material thickness, so we should throw out the thickness of corrugated paper.

The throwing power of color box and cowhide carton is different.

Take the color box as an example: the length, width and height of C tile can be increased by 0.3~0.4 cm respectively.

[8 x4)+0.4]X[( 12 x3)+0.4]X( 18+0.4)

32.4 X 36.4 X 18.4 cm

The next step depends on whether you want a tall box or a short box.

Usually (1) tall boxes are placed vertically (for products like beer boxes):

36.4 X height 18.4 front design,

32.4 X 18.4 edge,

Opening position: 32.4 X 36.4

Or (like a boxed milk carton)

32.4 X 36.4 is the front.

36.4 X 18.4 edge

32.4 X 18.4 Kaifeng

And so on.

The color box design is basically the same as the inner box packaging design.