A carton is a basic container usually designed to contain food or other household products. Several cartons are a simple box shape, but probably the most popularly recognized is milk containers which have what is called a gabled top. Drawing a three-dimensional milk carton can be learned by following a few easy steps.
Draw a rectangle using the ruler. For milk cartons, it should be taller than it is wide. For egg cartons, it should be much wider than it is tall.
Draw a triangle on top. The bottom side of the triangle must be the same line as the top of the rectangle. Both top sides of the triangle must be of equal length. Draw an additional short, vertical line arising from the pointed top of the triangle. You now see the carton in profile. If you want to draw a simple box shape or egg carton, ignore this step.
Draw four straight parallel lines of equal length going diagonally up from the left side of corners of the profile. One should emerge from the bottom left and top left corners of the rectangle, one from the top of the triangle and one from the top of the vertical line. Make sure they are all parallel to each other and of equal length. If your carton is a simple box shape or an egg carton, ignore the second two lines and draw a third from the top right corner of the rectangle.
Draw three more lines connecting the parallel lines to each other. If you are drawing the simple box-shaped carton or egg carton, draw two instead. You now have the essential shape of a carton. For egg cartons only, continue to Step 5.
Draw six equal curved shapes of equal distance from each other along the bottom of the box shape. Draw a seventh curved shape of equal size above and to the left of the left-most of the first six curves. You now have a basic egg carton.
Look at a carton from different angles and practice drawing it. These will build basic three-dimensional drawing skills.