Systems and methods for improved flexographic printing with reduced mottling and increased highlight stability

A flexographic printing system for improving screening of a continuous tone image to increase stability in flexographic printing, comprising:

• a computer system configured to (a) receive a plurality of settings for a screening process as input by an operator, wherein the settings include (i) a first changeover point to switch between application of an amplitude modulation screening technique and a frequency modulation screening technique within a highlight area of the continuous tone image and (ii) a second changeover point to switch between application of the amplitude modulation screening technique and the frequency modulation screening technique within a shadow area of the continuous tone image and (b) perform the screening process using the settings input by the operator, wherein the screening process comprises:
• receiving the continuous tone image, wherein the continuous tone image includes one or more highlight areas and one or more shadow areas;
• converting the continuous tone image into a plurality of halftone graphical elements to create a proposed graphical input, wherein the first changeover point is used to determine whether to use the amplitude modulation screening technique or the frequency modulation screening technique when creating the halftone graphical elements within each of the highlight areas, and wherein the second changeover point is used to determine whether to use the amplitude modulation screening technique or the frequency modulation screening technique when creating the halftone graphical elements within each of the shadow areas;
• and
• a flexographic printing device configured to expose the proposed graphical input onto a flexographic printing plate.

A method of improved screening to reduce mottling in flexographic printing performed by a flexographic printing system, the flexographic printing system including a computer system and a flexographic printing device, the method comprising:

• using the computer system to perform a screening process comprising:
• receiving a continuous tone image;
• converting the continuous tone image into a plurality of halftone graphical elements to create a first proposed graphical input,
• identifying at least one high density region in the first proposed graphical input;
• identifying an edge of each of the graphical elements within the high density region;
• identifying a plurality of candidate pixels within the high density region, wherein the candidate pixels exclude one or more pixels that are within a pre-defined distance from the edge of each of the of graphical elements within the high density region;
• removing each of the candidate pixels from the first proposed graphical input to create a second proposed graphical input, wherein the one or more pixels that are within the pre-defined distance from the edge of each of the graphical elements within the high density region are not removed so as to provide edge protection during pixel removal;
• and
• instructing the flexographic printing device to expose the second proposed graphical input onto a flexographic printing plate.