Inspiring

Answered

white overprint

Forum|Forum|2 years ago
January 24, 2024
8 replies
6613 views

I need to print on cardboard in white and 2 other colors. Black, pantone, white. Each of these colors must be overprinted. I can't define white though. If I put a fifth white color rgb or cmyk and then overprint, on the sheet it disappears when I create the pdf. On the one hand I understand that overprinting white does not return anything, but we are talking about a fifth color so this approach does not make sense. Can anyone help me with this?
I tried creating a fifth color c1 m1 y1 k1 to see if it changed anything by assigning a minimum value for each channel, but this is not the solution. I would like to have on the pdf if I deselect the "white" channel the elements disappear as with the other colors and reappear when I reactivate it, but white always punctures my underlying layers and if I deselect it nothing happens--because it punctures the color layers.

Translated with DeepL.com (free version)

Print

This topic has been closed for replies.

Correct answer Lukas Engqvist

Note that for Separation Preview to work you need to have the Transparency Blend Space to be CMYK mode. CMYK 0,0,0,0 is not white but paper colour. If you have Overprint enabled then it is transparent (but it will warn you), note that Overprint is irrelevant in an RGB document.

In Separation Preview, you will see additional inks besides CMYK, and you can view then together or separately to analyse your work. I normally place opaque white, above other colours even if it will be printed first. This way it is easy to toggle on and off. Let it be a colour you can distinguish from the white of the "paper".

Normally white ink (as spot colour) is created using a Spot colour with a pink or green appearace, so that you can see where it is (since the artbaord is white.)
Pantone white is not good white though, but UV printers using a RIP like Onyx use a spot colout called "Ink_White" for mapping to an Opaque White ink.

A spot colour with overprint should not knock out other layers… I do it all the time). This process is also used for Cut, Crease, Embossing, Varnishes and/or Foil where it is also impossible to visuallise correctly. (In Adobe Illustrator the Plugin ESKO Studio is used in many pcakage desugn firms where they need to visualise speciality inks, but it is still possible to design and proof, using experience to evaluate the results.) When one channel only is visible, then you will also see it as a film where the areas of ink are shown in Black, even if the ink in you press will be white.

Please if you share an example of how you are experiencing your work (a close up is fine) with the Separation Preview clearly visible.

Overprinting is a per channel operation so if you have a CMYK image and overprint a low percentage 1% in a Process colour it will limit that Colour to the top %, and it appears knocked out but it isn't, it's the 1%. In some rare cases you will not be able to Overprint but can use the "Darken" blend mode (Even if it is a lighter colour.) Think of Darken as "And also add this colour", so a Varnish, Metalic or white will not actually make the image darker. Avoid using Other bledmodes that use multiplication when mixing Spot colours, Multiply should not be used with Spot Colours. Some Transparency or effects may interfere with spot colours, but Separation Preview should help you trouble shoot.

Lukas Engqvist

Correct answer

Community Expert

Note that for Separation Preview to work you need to have the Transparency Blend Space to be CMYK mode. CMYK 0,0,0,0 is not white but paper colour. If you have Overprint enabled then it is transparent (but it will warn you), note that Overprint is irrelevant in an RGB document.

In Separation Preview, you will see additional inks besides CMYK, and you can view then together or separately to analyse your work. I normally place opaque white, above other colours even if it will be printed first. This way it is easy to toggle on and off. Let it be a colour you can distinguish from the white of the "paper".

Normally white ink (as spot colour) is created using a Spot colour with a pink or green appearace, so that you can see where it is (since the artbaord is white.)
Pantone white is not good white though, but UV printers using a RIP like Onyx use a spot colout called "Ink_White" for mapping to an Opaque White ink.

A spot colour with overprint should not knock out other layers… I do it all the time). This process is also used for Cut, Crease, Embossing, Varnishes and/or Foil where it is also impossible to visuallise correctly. (In Adobe Illustrator the Plugin ESKO Studio is used in many pcakage desugn firms where they need to visualise speciality inks, but it is still possible to design and proof, using experience to evaluate the results.) When one channel only is visible, then you will also see it as a film where the areas of ink are shown in Black, even if the ink in you press will be white.

Please if you share an example of how you are experiencing your work (a close up is fine) with the Separation Preview clearly visible.

Overprinting is a per channel operation so if you have a CMYK image and overprint a low percentage 1% in a Process colour it will limit that Colour to the top %, and it appears knocked out but it isn't, it's the 1%. In some rare cases you will not be able to Overprint but can use the "Darken" blend mode (Even if it is a lighter colour.) Think of Darken as "And also add this colour", so a Varnish, Metalic or white will not actually make the image darker. Avoid using Other bledmodes that use multiplication when mixing Spot colours, Multiply should not be used with Spot Colours. Some Transparency or effects may interfere with spot colours, but Separation Preview should help you trouble shoot.

S

stefanofeAuthor

Inspiring

In any case, I wanted to say this to everyone who made suggestions:
smart solutions stay smart. Many of you suggest this and I don't want to diminish that. But I have a white brush and a black wall in my hand. Brush white on black. I don't want to use chemical tricks to get white... I just want to brush knowing that my brush has a covering white pigment. Imagine if you had to use chemical devices despite the covering pigment. I don't belittle the intelligence of those who succeed. I only ask that you provide tools for fools like me who simply want to use a brush.

James Gifford—NitroPress

Legend

I was pretty much done here, but since you insist on insisting to insist you're right —

Have you ever checked with an actual commercial printer about the viability of white overprint?
Do you have any example of a print job where white ink overprinting created a satisfactory result?
- Subquestion: does the layout term 'knockout' mean anything to you?
Has it occurred to you that the mature, professional layout tool throwing a barrier to your demand for white overprint is perhaps (technically/programmatically) smarter that you are? And that a cheap alternative tool — a very good one, for most layout and print design purposes, but still a fairly low-end knockoff — might be allowing you to set up a white overprint not because it's nice or agrees you're smart... but because it is (technically/programmatically) too stupid to know that's not a good/valid option?
- (Exercise for the student: come back with 100 words about the fundamental difference between Photoshop and GIMP, the latter of which some large population insists is just as good as the former. Hint: start with "CMYK.")

And, really, the key question:

When you have this job run, will you report back honestly all exchanges with the printer and the quality outcome of the job?

Since the likelihood is that you'll respond with four "No's" I'll include a softball question to let you throw in a Yes:

Are you convinced that some century-odd of combined experience here is simply pigheaded Adobe defenders who won't admit that you can "brush" white over color on an offset press?

Peter Spier

Community Expert

This seems like a great feature request....

When the [Paper] color is redifined to match colored stock, allow a white spot color.

Peter Spier

Community Expert

In the meantime, if this is just to get a proper visual preview as Jeffrey suggests, a second file with a colored background and white elements using [Paper] might suffice.

S

stefanofeAuthor

Inspiring

question not at all professional and safe. We are human beings... if you have 2 files to manage a single solution, an error related to double management could occur. Sorry... I'm not asking for such a complex question... simply a flag that distinguishes the spot color allowing overprinting. You need to know that there is a difference between the white of a watercolor and the white of an oil colour. Dear Adobe... I'm asking for a flag.

J

Jeffrey_Smith

Community Expert

There are times in graphic design that one may need to create a file to simulate the results of final intent, and then create a completely different file that would suffice the production needs of overprinting, proper color separation etc.

S

stefanofeAuthor

Inspiring

in some cases this is complex to achieve... I am in one of these cases.

S

stefanofeAuthor

Inspiring

exactly this. I tried, but I couldn't do it. c1 m1 y1 k1 - spot tint - overprint - and I have an empty channel. but I'm still trying. Anyway if I define as 5 color a white...why on earth do I have to assign values to the tints? This is a serious error by Adobe. The 5 color can also be a transparent lacquer!!!!

James Gifford—NitroPress

Legend

Both (some instances of) Black and (nearly all instances of) White are special cases in print graphics. It's inherent to assume that any use of white is meant to represent an absence of ink applied to (usually) white stock. I am not surprised you're getting stubbornly "normalized" results, and I'd bet there is no good ("official") way to bypass them.

Unless you are doing digital printing, where the color mix will be transferred directly to the printer — that is, assuming you're designing for plate and ink printing — just use a reasonable substitute color that the export system won't interpret as "white/blank" — something with enough defined tint to avoid that classification — and I suspect you'll have no further problems. It will be up to you to differentiate between a preview/proof image with white elements, and the export/RIP setup that will generate a proper "White" plate.

S

stefanofeAuthor

Inspiring

I disagree. Instead, I say that the preview must follow my intention. If I say that a text is white in overprint ... the white is no longer the white of the paper, but of a pigment. But you have to explain to me the difference that there can be between a cyan 100 dye and white 100 for a software. I told you. a simple flag is enough! Just put it on though. The flag tells the software that I want an opaque tint.

J

Jeffrey_Smith

Community Expert

Keep in mind if you are creating a spot color that is white, with overprint applied, and is over top of another element, the PDF in Acrobat (Overprint Preview) will dislay this in a way that will make the white disappear.

S

stefanofeAuthor

Inspiring

exactly this is the problem! But I turn to Adobe who is supposed to be the leader in the printing industry and they can't handle me an opaque white! And don't ask me to use cyan or another color! I say if I have an opaque white paint.... you have to know how to handle it: it is not a transparency: it is a color!
Photoshop was not born with transparency ... and now I can't handle spot colors?