How to enable overprint in text with black to gray gradient?

[Johnny Chin]

How to make black to gray gradient on text to have overprint after export as pdf?

I select overprint in pdf export panel but it doesn’t have overprint shown in indesign

I then create a 90k black and 85k black in swatch with overprint but then overprint don’t show up either after place into indesign, what’s going on?

[lacerto]

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[Lee D]

Are you using a particular PDF X preset or is this occurring with any and are the Overprint colours Spot?

[lacerto]

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[loukash]

On 3/17/2020 at 8:22 PM, Lagarto said:

overprint takes place only if they have been defined
as PMS values

Doesn't work for me at all.
Is it broken again? Or only on Mac?
APu 1.9.3, El Capitan

[lacerto]

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[lacerto]

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[loukash]

1 hour ago, Lagarto said:

worked around by using transparencies (not as part of a gradient but created with the transparency tool), and PDF/X-4 export method.

I see, thanks.
At least something…

[loukash]

2 hours ago, Lagarto said:

i suppose the feature is broken

I don't get it…

I still keep v1.8.4 as a "reserve". So, what I did:

1. removed (renamed) ~/Library/Application Support/Affinity Publisher folder to start anew there
2. but kept existing ~/Library/Preferences/com.seriflabs.affinitypublisher.plist (that's where the majority of app preferences are being saved)
3. launched v1.8.4 and created a new CMYK document
4. added a bunch of regular spot swatches plus duplicated them as global overprints
5. created a bunch of gradient rectangles and text blocks using the overprint swatches and K100
6. exported as PDF/X-3
7. say what?! all overprints are there and intact!

spotoverprint184.afpub
spotoverprint184.pdf

Next up, I have restored my original ~/Library/Application Support/Affinity Publisher folder, reopened the document with 1.8.4 again.
Overprint still working.

Next up, I have opened spotoverprint184.afpub with v1.9.3, exported as PDF/X-3.
Overprint still intact!

Next up, I have added a few text blocks more, using the existing swatches from v1.8.4, exported as PDF/X-3.
Overprint still intact!
spotoverprint184to193.afpub
spotoverprint184to193.pdf

Next up, I have created a new CMYK document with v1.9.3, added a bunch of regular spot swatches, duplicated them as global overprints, yada yada, same as before.
Gradient overprint still works!
spotoverprint193new.afpub
spotoverprint193new.pdf

WTF was going on there?
Did v1.8.4 perform some kind of cache cleanup or what?

What often is broken but for some reason works sometimes:
Gradient fill using two or more global spot swatches set to overprint.
A no-brainer in InDesign, sometimes it either converts to CMYK or doesn't overprint in Affinity.
And then, suddenly, sometimes it works.
spotoverprint193new3.afpub
spotoverprint193new3.pdf

WTF?!

[loukash]

For illustration, here the Acrobat screenshot from spotoverprint193new3.pdf (PDF/X-3):

The cursor was hovering over the "l" in "black".
The green spot plate has no knockouts whatsoever.
Also, some odd things may happen where two overprinting gradients between two different spot colors overlap…

[loukash]

I'm beginning to see a pattern why my above example has "worked":

• no CMY
• spot colors overprint

As soon as I change the background to regular spot or CMY, the overprint gradients will die.
Need to do some more tests, but as it seems, a swatch can be be either overprint or not. When I'm using only overprint swatches, everything works as expected.
Also, even if objects don't overlap, z-index makes a difference!

Definitely a bug, not a feature.

@Serif, we need object based Overprint attribute, now!

[lacerto]

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[loukash]

4 hours ago, Lagarto said:

1.8.4. might actually be the key

Upon wasting even more time with further tests:
Nope.

Some metaphysical keys I've found in ADe 1.9.3 (MAS version) and exported as PDF/X-3 are:

• creation sequence of objects
• z-index
• CMY(K) background

It's nuts, but there is a pattern.
For sure is that CMY(K) background breaks K-tint overprint incl. gradients. Always.
The z-index thing for overprinting spot gradients can be fixed by fidgeting around with the layers to find a sweet spot where it works.
Why the creation sequence matters and what steps should be avoided or followed while building up a document: no clue yet.

The Super Bad Fonky Thang® is that you can only tell what's happening by exporting to PDF and inspecting the separations in Acrobat because, eh, you know why, right…

Exhibits:
overprint193.afdesign
overprint193.pdf

I didn't track the creation sequence because I only figured that out when almost finished.
The numbers denote z-index, the layer with the background color labels being z=0.
The cursor is approximately where it says "#10", showing that under certain ideal conditions, Affinity can do what it's being told even with complex overprint scenarios like a spot background overprinting a CMYK background while being overprinted by spot gradient text…

And on a second thought, I wouldn't be all too surprised when in the end it boils down to a bug with – or a flawed concept of – the "auto-overprinting" K.

 

Layer hierarchy:

 

Edited April 23, 2021 by loukash

[loukash]

Key #4:

To overprint K tint gradient, it must be Artistic Text.

Unless when overprinting CMY background which will never work with tints, as demoed above.

Whereas K gradients in Text Frames will never overprint, even if it's a K100 to K100 "gradient". They can also break other text gradients from overprinting.
Spot gradients in Text Frames do overprint if having the "correct" z-index, unless the text frame background is CMYK.
CMYK objects with high z-index may kill overprinting for spot gradient text, even when they don't overlap.

Hierarchy matters.
Keep spot colors on top of CMYK when possible.
To knock out overprinting spot objects with CMYK, subtract them.

Oh well…

More food for thought:

spotoprint193.afpub
spotoprint193.pdf

[loukash]

Alright, a dirty little trick how to "overprint" a CMY and a spot background at the same time with a K gradient:

And the trick works like this:

We need to clip both backgrounds because clipping the magenta background breaks the text overprint for the spot background.
So the clipped backgrounds are now overprinting the black text, not vice versa.

[lacerto]

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[loukash]

6 hours ago, Lagarto said:

And contrary to what you mention above: on top of CMY and in text frames (do not need to be artistic text).

Sorry, perhaps I didn't make it clear enough: Spot colors will overprint on CMY and in text frames. That includes black spot colors, of course. The thing that can break them is their z-index relative to other CMY or K objects and to non-overprinting instances of the same spot color. I already have a vague idea what the "scheme" could be, but no time today to investigate it in deep.

6 hours ago, Lagarto said:

"Why do stops stop accepting spots?"

6 hours ago, Lagarto said:

I cannot deduce from the UI whether the setting actually works so I need to create PDFs and use Adobe Acrobat Pro to see whether the setting really works*).

Yep, that's the real pain in the butt here.

6 hours ago, Lagarto said:

This works with any PDF/X method, and also with plain vanilla PDF (press-ready).

Of course, because it's spot colors at the "correct" z-index.

6 hours ago, Lagarto said:

The CMYK-based K gradient would still overprint only when using tricks like transparency or multiply blend mode.

The best workaround to avoid transparencies and thus possible inacceptable rasterizing on X-1 & X-3 output that I'm aware of so far, is my "clipping trick" above.
However, transparencies are less of a problem when overprinting a pixel layer, so using transparency gradient for K text seems to be OK there.

6 hours ago, Lagarto said:

(or should we just call it a bug)

Yup, let's call it by name.
Anything that requires that amount of user's time and work to investigate and comprehend, is a big, fat bug!

[loukash]

P.S. pinging @Lee D for giving more insight, thanks

[lacerto]

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[loukash]

3 hours ago, Lagarto said:

This one has chances of becoming chosen a workaround of the year 2021

What the…?
And I was under the impression that I would have tried that yesterday as well and that it didn't work?!
Apparently I only had the thought but forgot to execute it.

Congrats, you won!

[loukash]

3 hours ago, Lagarto said:

K100 to K50 frame text overprinting on top of CMY

Nah, still doesn't work for me.
It works as a regular K<100% tint overprint on CMYK which is a Great Thing™.
It just doesn't work in gradient.
Why?
Is the third stop the "secret ingredient"?

[lacerto]

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[loukash]

1 hour ago, Lagarto said:

I cannot reproduce it consistently

Now I can.

[loukash]

1 hour ago, Lagarto said:

first assigning PMS Black C to the text frame

Exactly. It can be any global overprinting spot color. My dummy spot is white, hence it won't even be visible in the composite overprint preview.

1 hour ago, Lagarto said:

the frame has the PMS Black C assignment with an overprint attribute, which prevents the K ink to knock out

Obviously, as in "first come first serve".

1 hour ago, Lagarto said:

requiring that the K definition, too, has overprint attribute tuned on

It is possible with just the regular K as well, but only if the Magical Essence is also included. (Oh, and only from dusk till dawn, of course, while listening to Cosmic Slop by Funkadelic! )

1 hour ago, Lagarto said:

the weirdest method of applying overprint

Definitely!
It's brilliant method though, as long as your print guy gets the notion of not attempting to print any spot plates in case you never wanted any.

And now…

*drum roll*

1 hour ago, Lagarto said:

if I just could list the exact steps to create it so that it always works

I will record a screencast. Hold on a while, I need a "nightly snack" first…

[loukash]

Here we go: