Should I choose [Threshold] or [Toning] when exporting in duotone?
If a printer or publisher requests your data to be in monochrome, you can choose [Duotone(Threshold)] and [Duotone(Toning)] in the export settings
Whichever you choose will depend on how you created your data.
What does threshold and toning mean?
The [Threshold] and [Toning] options are used to specify how grayscale and color gradients will be converted into monochrome.
The options are irrelevant when exporting data that has been made in monochrome.
Example of a duotone image
If your line art is anti-aliased or you have shaded using gray instead of screen tones, read the following to figure out the best export settings.
Anti-aliasing example
Grayscale example
Duotone(Threshold)
Depending on the color density, colors will be converted to either black or white.
If the screen tones are dots and the line art/text is not anti-aliased, [Duotone(Threshold)] is preferable.
Duotone(Toning)
With toning, images will be converted to monochrome dots based on density to simulate gray shading.
If the area that should be in screen tones is painted in monochrome, Duotone(Toning) is preferable.
When exporting in duotone:
As shown in the figure below, if line art is anti-aliased and the screen tones are in grayscale, accurately converting both will be difficult.
When exporting with [Toning]
The tone part will be converted without any problem, but the anti-aliased part of the line art will also be converted and rough up the line.
When exporting with [Threshold]
The line art looks fine, but the screen tones will be converted into uneven black and white segments.
To cleanly convert similar images, convert the line art into a duotone, or turn on [Tone] for the tone layer beforehand.
(1) Duotone
* After adjusting the threshold value, click [Apply expression color of preview] to confirm the monochrome conversion.
(2) With screen tones on
Example of proper monochrome conversion of line art and shading