Illustrator rounds up decimal places of a swatch LAB values.

[Birx]

I need to assing my design a specific spot color with certain lab values with decimal places, but Illustrator rounds up the values as soon as I input them. Is there a quick fix, with Illustrator settings or how can I make it work?

[Ton Frederiks]

Does it make a visible difference? I suppose that a spot color is mixed by the printer according to the Lab values and that the values in Illustrator are only used for preview.

[Birx]

I think there is a difference, in preview the color looks at least similar, but after printing client claim that the tone aint right. They game me lab exact values, for their spot color which it should ...seems that illustrator rounded those values, and the result aint what it shpuld be. 

[Test Screen Name]

Rounded, from what, to what? Every app is going to round to a certain number of decimals, and this won't necessarily match. That's just maths, nothing is broken. If the value actually changes, rather than being shown rounded or truncated to a fixed number of decimals, something may be wrong.

[Birx]

My values:

88.5 - rounds 89

2.0

3.4 - rounds 3

[MarieMeyer]

The difference between L88.5 A2 B3.4 and L89 A2 B3 is less than 0.5 using the CIE 2000 method. It is not perceptable to the human eye.

And, as far as I know, no, it is not possible to stop any Adobe product from rounding the LAB coordinates.

[Test Screen Name]

This rounding is expected. The software is set up to show 0 decimal places. 

[Ton Frederiks]

If they print a spot color, they print with a mixed ink the values in Illustrator do not matter at all for an additional ink. On what device do they print? You cannot print Lab, it has to be converted to process inks or mixed to a spot color ink.

[ColorWhiz]

Yes it makes a difference

Functionally - the difference is in how Illustrator-created files interact within InDesign

If InDesign is using the accurate swatch, which has two decimal values, and the Illustrator-created file is placed - the swatch is not 100% consistent within the working file and does not print the same.

Visible differentiation
Yes there is a difference. Depending on the person viewing, perception can be visible less than 1 delta, even if "studies" say otherwise.

Brand difference
It is a requirement by brands at a certain level to retain 100% accuracy and consistency from print partners, which absolutely require two decimal values in their delta variance equations. 
When source files are rounded by .5 in either direction, Already the file is incorrectly skewed from brand standards.

IMO this is a simple ask for continuity between design applications within the Adobe suite. InDesign supports two decimal values, global print partners require two decimal values for 100% accuracy in determining delta variance, Illustrator needs to support two decimal values in LAB swatch assignement. 

Please keep us up to date in how when this will be fixed.

TIA

[Ton Frederiks]

You may want to vote here:

https://illustrator.uservoice.com/forums/333657-illustrator-desktop-feature-requests/suggestions/461...

[ColorWhiz]

Yes, I have done that already. Was hoping for some more clarity on when this would be implemented, considering it's currently not compatible with InDesign in this regard. 

[Monika Gause]

This is the Community forum. 

If you have voted for the feature you will receive updates.

In this forum we do not know about the roadmap.