Difference between spot color and four-color iron box printing

Four-color printing

Four color printing is printed with four base inks, blue, red, yellow and black, using offset printing method (like paper printing). Different images can be printed. When viewed with an expansion mirror, the upper side has dots (like the flash of a TV, it has pixels, and after being expanded N times, it is composed of dots

Spot color printing:

Spot color printing is to adjust the ink according to the color on Pantone color card, and then print. Only one color is needed for printing. Of course, according to your plan, there can be images of different shapes. Several spot colors together form images of different colors, because the spot color is not a collision color, because there is no dot on the surface, it is relatively smooth