How to pantone color match spot colors on colored paper?

[realmstar]

How do you pantone color match spot colors on colored paper? For instance say all these spot colors are printed on a very light blue printed paper, the colors won't show up the same color as if they were on white paper which would make it easy to pantone color match. How would you go about it if all the spot colors are printed on light blue printed paper?

 

[realmstar]

Let me be clear. The colors you want to match are printed on the light blue printed paper. How can you figure out what pantone colors those are since the colors will show a bit different being printed on light blue printed paper?

 

[realmstar]

Someone left a very good response and now its deleted. That's strange why do post get completely deleted?

 

[Stephen Marsh]

Using a spectro, one can measure the result of the ink on coloured paper and compare that to a standard reference. Some spots will show through more than others for a solid. Tints will of course be more problematic.

Over and above going “by the numbers” with measurements – there is the human visual system to take into account, where the coloured background will alter perception of the printed colour – even if the spectro reports the spot on coloured paper as being the same colour as on white.


Stephen Marsh

 

[dabob]

D Ink Man . . where are you???????

 

[gregbatch]

I only did this once and it was a rough and simple method, but it came out perfect. With a color measurement device of your choice - I used a Pantone Color Que - Measure the spot color as CMYK. Then measure the paper as CMYK. Now subtract the paper values from the spot value. I entered the resulting CMYK value into Photoshop and mapped to the nearest spot color. I'm sure it was pure luck, but it worked perfectly.

 

[realmstar]

I was thinking the same thing! If I color matched the blue background then how do I turn that receipt into a digital one so I can also do this? For instance if it was half a pound of yellow and a quarter pound green. How would I turn that into a digital value?

 

[cnygmc15]

Your ink vendor can do this for you.........

 

[Correct Color]

How do you pantone color match spot colors on colored paper? For instance say all these spot colors are printed on a very light blue printed paper, the colors won't show up the same color as if they were on white paper which would make it easy to pantone color match. How would you go about it if all the spot colors are printed on light blue printed paper?

First thing to do is to tell the client that this is going to cost them some extra money. Keep in mind that in actuality, all any Pantone color is is an ink formula. If you make that ink formula correctly, and print it properly, then whatever color you get on whatever media you use is that Pantone color. That's why they make more than one book.

Second thing to do is to understand that even if you set out to do this, there are certain colors for which it will never work. For example, if you're trying to print a blue that's darker than your light blue sheet, you can obviously get pretty close by subtracting some amount of blue from your formula, be it ink or digital. However, if you're trying to print yellow on the same sheet, there's no blue to subtract, and you're never going to get there. Or if you're trying to print a light blue that's lighter than the sheet, you obviously can't get there, either.

What gregbatch suggested might be worth trying, although I'd use L*a*b* and not CMYK values. All any digital Pantone color is is a name and a L*a*b* value, and by working with L*a*b* values, you'll get a more predictable and consistent result.

Of course that all assumes you're creating "spot" colors digitally, and not traditionally physically making the ink. If you're physically making the ink, myself, I'd just make the colors opaque.

(Edited to add: It's probably worth adding that the way any digital spot color is printed is that the RIP looks for the named spot color L*a*b* value in the destination color space, which is the printer profile. The always works in theory, but how well it works in practice is determined by how closely the printer profile matches what the printer actually prints. So the very best and most accurate way to do this would be to make a profile of the particular media. That way the light blue becomes the media white point, and the RIP will get to the closest possible match, regardless of the incoming color.)



Mike Adams
Correct Color

 

[Michael Smith]

anytime we print PMS on colored items we have to use a white base.
other of our print processes we can add additives to the ink and make it super opaque.

 

[realmstar]

What additives can you add to ink to make it super opaque? Like if you were to want to print opaque white to black paper? What additives can you add to make it super opaque?

 

[gordo]

What additives can you add to ink to make it super opaque? Like if you were to want to print opaque white to black paper? What additives can you add to make it super opaque?

I don't think you can. Much easier to print black on white paper and reverse out what you want to be white.

 

[realmstar]

I don't know of anything either but Michael Smith says he uses additives to make ink super opaque so I wonder what he adds?

 

[Alois Senefelder]

I think that answer from M. Smith relates to "Silk Screen Printing" --- his job description relates to this printing method

Regards, Alois

 

[aqazi81]

I don't know of anything either but Michael Smith says he uses additives to make ink super opaque so I wonder what he adds?

May be he is adding Opaque white in Opaque white to make it super Opaque.

 

[D Ink Man]

It depends what color you are trying to achieve when printing a given color on light blue paper. It is best to stay away from opaque white, if you are able to achieve color using normal transparent ink.

To start, you have to think intently on the objective color. I will give an example with imagining a light blue stock and let us use pMS 185 red as the target. Instead of using 75% Warm Red / 25% Rubine I would start by printing warm red as is and see how the shade results vs. the guide. It is at this point where you can decide if you actually will need to overcome dirt and maybe have to even add yellow, to move further from the blue side. It is all dependent upon the stock, because the blend is still in a transparent state. If you are dirty in color, now is the time to introduce opacity to hide the stock which is creating the dirt. A good start for opaque white is 20%. Even better if you color can afford it is to add aluminum ink, or more commonly called silver. A good silver ink has much more hiding power or opacity versus TIO2, opaque white. You can add up to 8% without creating a metallic shade, just for the interest of opacity. Again, it all depends on the stock and the color target.

Best bet if possible is to send the substrate and spot color request to your ink vendor so they can match it, and provide the finished ink to you. It is an art and not a cut and dried process when dealing with matching colors on colored stock. Hope this provides some insight.

D Ink Man

 

[michaelejahn]

Let me be clear. The colors you want to match are printed on the light blue printed paper. How can you figure out what pantone colors those are since the colors will show a bit different being printed on light blue printed paper?

Sorry, but you are NOT being very clear - are you interested in:

A: using CMYK ink to SIMULATE a Pantone color when printing on light blue paper ?

or -

B: are you planning on using a spot ink and printing on light blue paper ?

Me, I would do what they do when they print the yellow pages - that is, they do NOT print on yellow paper, they print on white paper and they yellow you see is actually yellow ink ( yeah, don't believe me, get a loupe and see for yourself )

Also, if A, please explain to the customer that inks are transparent, so, that is totally impossible with light Pantone colors like :

http://www.pantone.com/color-finder/2001-UP

it will look green.

if B, then ( again ) same example, you can print white down first (so, white, then the pantone )

 

[gregbatch]

"I'd use L*a*b* and not CMYK values."

I thought of that too, but mathematically speaking CMYK was far easier to calculate. 75/5/100/0 - 20/0/0/0 VS 62.95/-47.984/40.342 - 90.585/-9.689/-12.903.

 

[D Ink Man]

Use the eye I think. That's what the man upstairs gave them to you for.

D

 

[realmstar]

I get what your saying. But even if I printed blue for the background that won't help me figure out the spot colors thats sitting on top of the blue? If I figure out the blue color then I could pantone color match the spot colors on top of the blue. Then I would just minus the blue color ingredients off the spot colors I matched it with. But how do I do that? If I know what the blue color is, how do I minus that off the spot colors sitting on top of it that I pantone color matched over top of the blue?

Sorry, but you are NOT being very clear - are you interested in:

A: using CMYK ink to SIMULATE a Pantone color when printing on light blue paper ?

or -

B: are you planning on using a spot ink and printing on light blue paper ?

Me, I would do what they do when they print the yellow pages - that is, they do NOT print on yellow paper, they print on white paper and they yellow you see is actually yellow ink ( yeah, don't believe me, get a loupe and see for yourself )

Also, if A, please explain to the customer that inks are transparent, so, that is totally impossible with light Pantone colors like :

http://www.pantone.com/color-finder/2001-UP

it will look green.

if B, then ( again ) same example, you can print white down first (so, white, then the pantone )