Each has different advantages, disadvantages, and costs. Gravure printing is done from large copper cylinders that are electronically engraved with microscopic holes, or cells. The cylinder is bathed in ink, which accumulates in the cells.
Excess ink is squeegeed off by a steel doctor blade.
Advantages of gravure are long press runs of consistently high quality, which makes it appropriate for packaging. Disadvantages are high costs for the gravure press equipment, and high costs and long turnaround time for cylinder engraving. Some packaging is printed by offset lithography, which is done from aluminum plates. Offset lithography is cheaper than gravure, but due to limitations on plate durability, it cannot print run lengths of more than a few million impressions. Flexography is printing from rubber plates.