Ink limit 320%

[mathiasmazzetti]

How do I keep inks below 320% for printing? Is there a way to limit these percentages directly in Photoshop or inDesign?

[rob day]

The CMYK profile you choose as the destination on a conversion from RGB (or Lab) determines the ink limit.

You can check the ink limit for a specific CMYK profile by converting 0|0|0 RGB black to the CMYK profile and checking the resulting CMYK values. After you have made a conversion a CMYK profile doesn’t prevent you from color correcting or building a CMYK color that exceeds the limit. If a printer requires an ink limit and wants you to make the conversion to CMYK, they should be providing a profile for their press.

[Michael Bullo]

The following notes and graphics refer to InDesign.

When creating your CMYK colours make sure that the combined percentages of the four individual colours don't exceed your 320% ink limit.

Within the Separations Preview panel you can change the View to Ink Limit and type in your own value. InDesign will overlay in red any colours on your page that exceed this limit.

[rob day]

The CMYK profile ink limit on conversions also applies to InDesign, so you might limit your CMYK swatch builds, but exceed the limit with placed images or RGB swatches.

The US Sheetfed Coated profile has a limit of 350%, so if I place an RGB image, InDesign’s Separation Preview will show the output values if that profile is set as the Destination at Export or Print:

If the document’s assigned CMYK profile is a newsprint profile, the total ink is much lower because ink is slower to dry on the absorbant newsprint—220% in this case:

The profile’s Ink Limit does not limit CMYK builds:

[SamBastion]

If you want to adjust the ink density of an image you can do it in Photoshop using either UCR (under color removal) or GCR (grey component removal)

check out this amazing looking website for more info 
https://web.tech.uh.edu/digitalmedia/materials/4373/color_rendering_intent/gcr.html

basically go Edit > Convert to profile

in the CMYK dropdown choose Custom CMYK

from there you can either reduce colour or grey to bring density down. be careful as colours will change so play around and see what best works for the image you are using.

[rob day]

Hi @SamBastion , while you can use Photoshop’s custom CMYK feature to make .icc profiles it’s important to note the resulting profiles are curve based legacy profiles. You can specify black generation and total ink with the Custom CMYK dialog, but curve based profiles are not as accurate as newer instrument read profiles, e.g. Coated GRACol, which are created by reading a color chart printed from a destination press. 

[SamBastion]

Thanks, you've sent me down a rabbit hole of colour now. I haven't had to deal with this kind of thing for ages. Looks like I have some reading to do. 🙂