M3 (Pol) measuring result on matt film lamination varies if change the direction of measuring device

[DeltaE]

Hello Experts,

I am not sure this post suitable here or in color management area, please move it to correct area if needs!
I have to measure a color sample which is printed a spot color - standard L*a*b = (48.6, -0.50, -2.16) after matt-film lamination.

Measuring condition is D50/10 and M3 (with Polarized filter). My device is a eXact Standard with M3.
Then if I change the direction of measuring device (the same measuring-spot) as the picture, I will got the measuring result variable, especially in L value - Delta L could vary -4, -2, -1, 0.5, etc, compared to the standard. I have tried another kind of matt-film lamination, adjusting the pressure of lamination machine. It still does not work.

So my question is: Do you know the caution of this phenomenon, what should I do for improvement?
I am very grateful for any idea and input from you!
Many thanks in advance.
Regards,
DeltaE

 

[Alois Senefelder]

Hello DeltaE,

An educated "guess" would be ---- Refraction of the Light via Laminate Film.


Regards, Alois

 

[SteveSuffRIT]

Do you gets same results with M0, M1?
Why are you using M3 Polarized?
How thick is the film?
As you rotate the finished laminated product, does it "Look" lighter and darker?
Matte film has a micro rough texture, maybe it has directional effects?

 

[RayC]

Hello Experts,

I am not sure this post suitable here or in color management area, please move it to correct area if needs!
I have to measure a color sample which is printed a spot color - standard L*a*b = (48.6, -0.50, -2.16) after matt-film lamination.

Measuring condition is D50/10 and M3 (with Polarized filter). My device is a eXact Standard with M3.
Then if I change the direction of measuring device (the same measuring-spot) as the picture, I will got the measuring result variable, especially in L value - Delta L could vary -4, -2, -1, 0.5, etc, compared to the standard. I have tried another kind of matt-film lamination, adjusting the pressure of lamination machine. It still does not work.
View attachment 290214

So my question is: Do you know the caution of this phenomenon, what should I do for improvement?
I am very grateful for any idea and input from you!
Many thanks in advance.
Regards,
DeltaE

Basically you are seeing the effect of double polarization - from the instrument (particularly in M3 which is polarized by definition) and this particular film. Not all film has a polarizing effect so this isn't always a concern. In the eXact the guaranteed way out of this problem is to measure in M1 - but given that you presumably were measuring polarized for a reason, the other option is to make sure you always approach the sample in the same orientation. BTW X-Rite has a nice technical note on this: https://www.xrite.com/-/media/xrite...per/l7-616_exact_xp_technical_paper_en_hr.pdf

 

[DeltaE]

Do you gets same results with M0, M1?
Why are you using M3 Polarized?
How thick is the film?
As you rotate the finished laminated product, does it "Look" lighter and darker?
Matte film has a micro rough texture, maybe it has directional effects?

Hi Steve,

The measuring value is constant if I use M0 (did not try M1 - but I guess it same as M0). The caution here, in my opinion, it is M3 (polarized filter) and matt film.
Our client requests us to use M3 (pol) D50/10.
When rotate the finished product, it looks same. Not sure about the thickness of the film
Checking by a microscope, I figure out the directional texture.
Thanks
DeltaE

 

[DeltaE]

Basically you are seeing the effect of double polarization - from the instrument (particularly in M3 which is polarized by definition) and this particular film. Not all film has a polarizing effect so this isn't always a concern. In the eXact the guaranteed way out of this problem is to measure in M1 - but given that you presumably were measuring polarized for a reason, the other option is to make sure you always approach the sample in the same orientation. BTW X-Rite has a nice technical note on this: https://www.xrite.com/-/media/xrite...per/l7-616_exact_xp_technical_paper_en_hr.pdf

Hi RayC,

Thank you for your interesting feedback!
But I got the constant value when I measured the client's sample, and with the same measuring condition I get the variable value when I measure out sample. So I guess the key point is type or kind of matt lamination film, but I am very lack of the knowledge of these lamination. Unfortunately, our client has taken their sample back, then we can not study it more now.