Preparation for Color Separation

In recent times, I have received several pieces of “finished art” supplied by clients where the sales representative has informed me that the printed material must be “on-brand” according to the client’s style guides. That should be the end of the story, but upon checking the finished art, it is clear that the artwork has not met the client’s own style guides, or been thoroughly checked by the client prior to submission.

One of two things will now happen – the prepress department can either fix the artwork without disturbing the client in order to fulfil the brief and expedite the work, or we can contact the client informing them of the situation and THEN ask whether we can fix it or have resupplied artwork that is color correct. Considering that the client may receive their proof and resupply the artwork in its entirety, this means fixing the colors again.

For years, I’ve been an advocate of receiving finished artwork that is correct for the following reasons:

  • The client has correct content;
  • Eliminates the risk of human error in prepress from incorrect or unintentional manipulations during corrections;
  • Prepress can output more work considering they are not spending time manipulating files that may only be replaced at a moment’s notice;
  • My employer isn’t losing revenue on prepress time that usually is not passed onto clients by the sales representatives.

That said, I make sure to contact customers who have supplied finished art that is incorrect and outline the issue, giving them the opportunity to resolve the issue themselves or let us do it. It is at this stage where some customers have been willing to fix the artwork themselves, but cannot see the issue. When I ask them to check the separations preview panel, the answer is always the same – “where’s that?”. Because this is a panel that I use so often as a prepress operator, I often think to myself “are you kidding me?” but to be fair, there are many panels in InDesign that I don’t use such as the animations panel; and I would have no idea how to use either.

On that note, I have prepared a video on my Youtube channel on how to use the Separations Preview within Adobe InDesign and used it to highlight instances of color mismatches, issues with black ink, and when white overprints.

This is not the first time I’ve been on my soapbox about this before – (see this article). It also directly relates to:

I’m gonna knock you out, my printer didn’t knock you out…

An earlier post “To Overprint or not to Overprint, Black is the question” explains how the colour labelled [Black] in InDesign behaves, and when solid black ink should and should not knock out of the colours behind it.

Paying attention to this advice and applying it to artwork should result in a good printed reproduction, correct? While the answer should be yes, there is one more level of control of black appearance and overprints, and that is in the hands of the printing company and their output software.

OFFSET EXAMPLE

Let us look at this following example:

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This card is set up for a Black plus spot output for an offset press. The Black is only overprinting on the text as misregistration would be noticeable here, but the Black elsewhere is knocking out so that the colour does not look muted through the yellow.

However, despite best intentions and checking the separations both in InDesign and Acrobat, the card has printed like this (effect is exaggerated for the screen):

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So what has happened? The separations were correct, they were checked in both InDesign and Acrobat! It turns out that the Raster Image Processor (RIP) software that the commercial printer uses to image the design onto the printing plates has its own settings. Here are some example screenshots from AGFA’s Apogee X system and Fuji’s XMF system respectively about the overprinting of black:

apogee

xmf

In both screenshots above, the respective RIP software CAN honor the settings that were in the initial PDF and not apply its own preferences, but in the instance of the business card, the RIP settings overrode the PDF settings and chose to overprint all instances of 100% black, regardless what swatches were chosen in InDesign.

DIGITAL PRINT EXAMPLE

Using the same artwork, the card was printed via a colour copier, but this time the result was as follows:

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So what happened here? The while the solid black looks good, where the black in the top line meets the vignette looks rather weak, and there are is a lighter black around the travel agent. What is going on?

Again, the RIP software has manipulated the artwork with unintentional results. Unlike printing directly to a desktop printer, most digital printers will print to a RIP where the file can be imposed, colour adjusted and printed in whatever order the prepress operator sees fit.

Using the EFI Fiery RIP, there is a little-known feature of the RIP that changes the way black is displayed that can produce unexpected results, and that is in the color settings dialog box and it is “Pure Black On”.

Screen Shot 2013-06-03 at 2.55.28 PM

This setting takes every instance of 100K and ramps the colour to a “super black” as opposed to using the black toner only. Again, this setting can be changed, but when this card was printed, the defaults were unchanged resulting in this unwanted appearance.

This setting only applies to vectors and text AFTER the PDF is flattened into postscript. This is visible where the rich black abruptly changes to the muted black. One look at the flattener preview in InDesign confirms that areas of flat black in that image were as a result of the flattening.

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THE RESULT?

This small example shows how changing the client’s intended black overprints can have unwanted consequences. For prepress operators it is a wake-up call to make sure that the RIP defaults will maintain the clients’ expected results; and for designers or publishers it is worth understanding that even the treatment of black overprint is an important topic.

You’ve gotta keep ‘em separated – check colour separations!

There is absolutely no doubt that submitting finished artwork as PDFs has eliminated several prepress issues such as missing links and (mostly) missing fonts. Sadly, it has not eliminated all prepress issues associated with submitting artwork. In this post, I would like to look in more detail at an issue which is to me a fundamental step before submitting finished artwork, and that is checking colour separations in a PDF – properly! Not doing so is a cardinal sin of prepress.

For this, I have created a mock-up black and two spot colour flyer for a favourite destination of mine, Montréal. On face value, the PDF appears to be fine, but after looking at the artwork in more detail such as the crop-marks and where the artwork bleeds, it is clear that the bleeds will need to be fixed.

This is issue one. The rest is fine, right?

No! To see the other issues, the output preview dialog box has to be open. To get there using Acrobat 9, go to the advanced tab, then print production… , then output preview

Suddenly, the preview changes a little. From here, it is possible to see checkboxes for both process plates and spot plates. This job is Black plus two spot colours, so all appears to be right so far… but what happens when the black channel is turned off?

Instead of disappearing, the black becomes lighter. This means that the black is not purely on the black separation, but rather all of the process separations. It should look like this:

So what is going on here? It would appear that the blacks are actually made of process despite appearing greyscale, the photograph may have been RGB or CMYK. The type, despite appearing black, may be made using RGB black. So how can this be determined?

In the output preview dialog box, there is a dropdown which says “Show”. By default, the dropdown result is All, and this means that all gamuts on screen are shown, but not necessarily what images are process, spot, RGB or LAB.

If the dropdown field is changed for example to RGB, it is possible to see what items on the page are RGB only.

After doing this, it appears that the type on the page is RGB which is why it isn’t colour separating properly into black. This means going back into InDesign and changing the RGB black to 100% Black. OK, one issue, but what about the masthead picture – that isn’t RGB. It is possibly made of a “faux black” out of process, so the dropdown needs to be changed from RGB to CMYK.

I can now see two things: what appears to be a black and white picture, and coloured type in the left middle of the page. To determine if the black and white picture is actually on the black separation only, the black separation has to be toggled off.

The image has become lighter, but not disappeared. This tells me that the image is made out of process instead of being greyscale. This means going into photoshop, making the colour mode greyscale, resaving, relinking in InDesign. That is two issues.

But why was there process coloured type? It should be two spot colour separations plus black. To check this, change the dropdown field to spot colour.

Now I can see the word Montréal in solid 494, the background in a tint of 494, and the strip of yellow 610. But the words “WHEN SHOULD I GO?” have disappeared. This infers that these items were not made out of spot colour, or they should be visible in this view. Instead, the items must be made out of process, as they were visible in the CMYK view, but not Spot Colour nor RGB views.

So after checking the PDF and its separations more thoroughly, I now know there are several fixes required for this PDF: The InDesign file needs to have the following changes:

  • Colour which extends past a trim area has to bleed off;
  • The RGB black type needs to be 100% black only;
  • The “black” photo of Montréal needs to be made greyscale;
  • The words “WHEN SHOULD I GO?” and yellow strip behind need to be changed from process to their appropriate spot colours.

I have prepared before and after PDFs for the purposes of trying what has appeared on this post.

Spot “color” of bother

Why converting spot colour to process on process artwork is not such a good idea.

Ever had a supplier make contact to say that there are spot colours in the artwork supplied, and wondered “Why don’t they just convert it and leave me alone? Why are you bothering me with such a simple thing?”

1) Possible breakdown in communication

For the art department of the supplier, this will normally be the first time that they have seen the artwork and be totally unaware of its history or construction. All the art department will normally be concerned with is that the details on the docket match the artwork, and that the artwork meets the mechanical specifications for the press, such as correct colours, bleeds, page size, etc.

For a prepress operator, observing a spot colour in addition to process artwork raises red flags such as:

  • Is the artwork actually meant to be CMYK+spot?
  • Is the artwork meant to be all spot colour?

Similarly, if a prepress operator receives artwork with instructions that the artwork is to print in Pantone Red 032 for example, but the file is prepared in Pantone Warm Red, the prepress operator will ask the question: is the colour being printed on the docket correct, or is the ink in the customer’s artwork correct? This is not uncommon problem in a printing business and is a great way of delaying proofs and creating confusion.

2) How the conversion is done

“Converting” a spot colour all depends on how the conversion to process is done. Take for example the color Pantone Red 032. Depending on which application made the PDF, the colour can appear with several breakdowns:

  • Adobe InDesign 5.0 (Pantone Solid Coated Library) – C0 M90 Y86 K0
  • Adobe InDesign 5.0 (Pantone Color Bridge Library) – C0 M90 Y60 K0
  • Quark Xpress 8.0 – Solid Coated Library OR Color Bridge (using the CMYK output) – C0 M90 Y60 K0
  • Quark Xpress 8.0 (using the CMYK and spot/As Is methods) – LAB colour

In addition to this, the printer’s RIP also has the ability to convert spot colours to process in a PDF based on the alternate value within the PDF, or a value based on a spot-to-LAB-to-CMYK conversion.

Furthermore, a customer’s corporate stylesheet may have several colours of a logo depending on the circumstance that the artwork is being used, such as:

  • if appearing in newsprint in process, use this breakdown;
  • if appearing on glossy stock in process, use this breakdown;
  • if appearing in newsprint in spot, use this spot colour;
  • if appearing on glossy stock in spot, use this spot colour;

3) If the PDF has transparencies, drop-shadows or the like.

If the PDF has been made to Acrobat 4 compatibility (1.3) and features drop shadows or any effects above a spot colour which was flattened once the PDF was made, then a spot to process conversion may not even be possible. Areas which were flattened will become white, as demonstrated in the illustration below.

4) The client’s expectations of spot v process

Some spot colours such as metallics, fluoroescences, pastels etc convert terribly to process, regardless of which method to convert them was used. If the client has chosen spot colours from a swatch book with no process equivalent next to the swatches, and expects these colours to reproduce out of process colours and look identical to the swatch book, then they are setting themselves up for failure.

Some swatch books (such as Pantone Color Bridge) does display its swatches with the spot colour on the left and how it appears converted to process on the right.

However, if a customer is shown a swatch using the book and it is not made clear between the difference in colour between spot and process, the customer will be disappointed once again.

The bottom line?

If artwork is to print process, prepare the artwork using process colours only. If the artwork is to print in spot colours, make sure that the spot colours in the document are going to be the same spot colours going to press. If your client has supplied you spot colour artwork which should be process, ask them to supply process artwork. If they complain and ask why, point them to this article.

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