Pantone ink color shifting

[gordo]

I think that most of us have been hit with an unpleasant surprise when a Pantone ink color shifts because of UV, aqueous, or laminate coating.
I'd like to hear about your experience with any specific Pantone ink that shifts color dramatically because of UV, aqueous, or laminate coating.

best, gordo

[saso777]

Hi Gordo,
It happened last year we print some boxes for ice cream,4color+Rhodamine Red+PMS Purple so print them perfectly but we UV varnish them after 12-14 hours so next day it was real disaster,inks changes dramatically and we had to repeat whole job again but this time we put water base varnish first and after that do UV without problem.

[chevalier]

We have an in-plant ink lab and nearly every job we produce has a spot color in it. While this isn't practical for the average shop we prevent this by producing an ink match of the production ink on the production stock and apply the exact coating or varnish or combo of the two upon it and send that directly to the customer for approval prior to production.

Alternatively if you are not mixing your own ink and ordering it from a vendor. MOST vendors will produce ink matches for you in their own labs.

[Bob Peterson]

When mixing and/or ordering PMS colors or matches be sure to inform your ink vendor that you will be aqueous or UV coating the job.

The following colors below will bleed and/or burn out when subjected to the alkalinity of a aqueous or UV coating. I have listed the PMS mixing bases and their coatable substitutes below:

PMS BASE --------------------------------- COATABLE SUBSTITUTE
Warm Red -------------------------------- Yellow Shade 2B Red*
Rubine Red <15% in the mix. ----------- Blue Shade 2b Red*
Rhodamine Red --------------------------- Quinacridone Red*
Purple ------------------------------------- No Exact Replacement++
Violet -------------------------------------- Carbozole Violet*
Reflex Blue -------------------------------- No Exact Replacement##

*NOTE: The shade is not an exact match and/or the pigment strength is weaker.

++NOTE: In some instances a mixture of Quinacridone Red & Carbozole Violet may suffice. This mixture yields a very dirty Purple.

##NOTE: Mixing PMS Process Blue & Carbozole Violet will yield a good match.

In order to save the costs involved with reprinting a spoiled job, it is best to communicate with your ink vendor all of the pertinent details pertaining to the job. This will insure you have the correct ink the first time around.

[fiatlux]

The following colors below will bleed and/or burn out when subjected to the alkalinity of a aqueous or UV coating.

Could you explain what is meant by "bleed" and "burn out"?

FL

[RGPW17100]

Could you explain what is meant by "bleed" and "burn out"?

FL

Alkalinity burn is the name given to the effect on inks that have certain pigments. These pigments have a reaction to the coating material and will react in different ways. The previous poster will be able to give you the scientific name and reasons my experience will give you an easier to understand explanation but may not be as correct. Reflex blue ( probably to nastiest color in printing) tends to print dark blue but will dry with a red tint to it. Aqueous coating attacks the pigment and in my experience does not allow the red to come out when drying leaving a dark blue with a black tint to it. If you print a reflex job with non coatable ink you have a nice rich looking blue red color that will not dry. So to make it dry faster you run it through the press again and put a coating either UV or Aqueous and you will see a color shift immediately however the complete shift will take a day or two to finish. The first thing you notice is the red is gone and it some how looks blacker.

On the reverse if you run a coatable reflex and you do not use a coating the color is all wrong. The colors effected by this burn is rhodimine, reflex, warm red, violet and purple. If you coat say pantone green, process blue or rubine you will see a negligible shift in color.

There is also a slight burn but not as pronounced when using over print varnish. It tends to burn out the reds but much less then coatings like aqueous and UV