Intolerant about tolerances

Designing print projects on-screen comes with a false sense of precision. It is easy to assume that whatever is designed on-screen will accurately reproduce – without flaws – into a real-world finished product. This is reinforced by the ability to place objects on precise coordinates and align and distribute with similar precision.

Unfortunately, the practical application of the design from computer to real world product comes with a series of tolerances that are not taken into account in the design software.

Such examples are

  • Variables in the substrate. Paper stocks can stretch, distort and swell based on humidity, storage conditions, temperature and ink density, just to name some variables.
  • Creep (aka shingling, pushout or thrust). This is covered in an earlier article, but it is the phenomenon of artwork in a book moving towards the foredges of pages due to the gathering of folded sections.
  • Registration between inks and Embellishments.
  • Precision of the paper folding.
  • What your computer says vs what the output device prepares.

Some tolerances are hardly noticeable and imperceptible without magnification, while other tolerances are large in comparison. This article will examine several print phenomenon and the tolerances associated with each phenomenon.

Tolerances in ink registration

This is an example where tolerances are quite tight, and best shown when printing several colours in one pass, such as full colour process offset printing, digital toner or inkjet printing. Take for example the following headline.

At normal magnification, the inks appear to be in perfect registration. However, when zoomed in, it is possible to see that the registration of the inks is slightly off, demonstrating tolerances in microns.

However, it doesn’t take much to make the tolerances worse, such as:

  • Using a printing method where misregistration is a larger concern, such as flexography or screen printing;
  • Printing additional colours on a second pass, meaning the sheets have to dry first and add the variable of paper distortion to trying to register the additional inks to the previously printed inks.

Embellishment registration

From here, tolerances begin to get worse. Take for example a full colour plus one spot colour print that has an additional spot UV clear varnish applied over the lettering.

Note that while the inks are in register, the spot UV is off by half a millimetre to the top right. This is because two separate processes were used – a five colour press to print the inks onto the paper; then the spot UV was applied using a screen printed stencil that was made using an imagesetter that was different to the platesetter that produced the images for the plates.

Another example is how a design translates from screen to embellishment. Take this complicated foil, and notice how the fine detail in the foil is lost.

Fold registration

This is where tolerances can be out by several millimetres. A simple exercise that demonstrates this issue is to take a sheet of paper and fold it in half four times, then look at how the pages line up at the heads and feet of the folded pages. The same issue occurs when taking an imposed sheet and folding it into a signature to combine with other gathered signatures for burst binding.

Take the following example that has a running header in InDesign where the sidebars bleed off of the foredge. Note the difference between the highest point vs the lowest point.

What can be done?

  • Know that printing and binding are not precise and subject to tolerances like any other manufacturing. What is important to know is where the extreme tolerances lie and how to design with them in mind.
  • Speak to your printer or finisher and ask to see samples of previous work.

There is also page to page registration that needs to be discussed, but this will be covered in a future Colecandoo article.

Consistent spot color naming to die-forme

A pain-point I see regularly concerns inconsistencies in color names, particularly spot colors that are used for embellishments. Take for example a color that is used for representing a forme-shape. For consistency sake, the office has implemented a CC library with standard swatches for regularly used embellishments such as Dieline, Perforation and Spot UV. The concept is that anyone who requires an embellishment can simply open the CC library and choose one from the embellishment colors that have been established.

Despite creating this CC library, embellishment colors and names can still be inconsistent for reasons such as:

  • The artwork was legacy artwork prior to introducing the CC library;
  • Operator error; or
  • Art was supplied by a third party, such as a client or supplier.

Naming consistency is important with workflows that have been established with these embellishment colors. Take the color “Dieline” for example. This should be clearly visible on the native files, but not on the printed output. In this instance when printing to digital devices, the RIP will identify the color “Dieline” and assign it a white color value that will treat it as if it were transparent and not print at all, though it will appear in the PDF. This eliminates the need to toggle a dieline layer on and off in the application that made the artwork, and eliminates any errors associated with art being mapped to incorrect layers.

However, if the artwork contained a color named as “Dieforme” for example, the RIP would not identify the color as “Dieline” and the formeshape would be visible on the final print. This issue could be resolved by adding the color “Dieforme” manually to on the RIP, but the concept is to have every file the same so that operators aren’t interrupted having to make adjustments on the RIP for specific tasks.

A solution via Acrobat

My preferred solution is to use a custom fixup from Adobe Acrobat’s Preflight dialog. In this example, I’ve created a PDF that contains ten variations of Dieline spot color using different names, but the color value is identical. Here is what the separation preview looks like:

Acrobat does have pre-made fixups for similar tasks, such as Make custom spot color names consistent.

Let’s give that a go.

The fix has reduced the number of spot colors but only down to five. Names that had different casing have been merged together, and spaces or dashes have been removed and then merged together with the results.

Let’s revert that and try an alternative fixup Merge spot color name if appearance is identical.

OK, that has remapped all of these spots to one spot color.

However, this color is the wrong name. It is also unlikely that the forme-shape colors would ever be set with different names yet have the same underlying CMYK color conversion. The following would be more likely:

Let’s run the Merge spot color name if appearance is identical fixup again.

Some names have been culled but there similar names such as die and Die have not been mapped together, so this solution hasn’t worked.

Make a custom fixup in the Preflight panel

Luckily we can make our own solution from the Preflight panel by clicking on the options button at the top right of the panel and selecting Create Fixup

In the new window, the fix will be given the name Diecut Fix. Choose Color spaces, spot colors, inks from the Fixup category in the top centre dialog; and select Map spot and process colors in the Type of fixup dialog on the top right hand side.

In the options at the bottom of that dialog box, make sure the Source color name matches with RegEx and in the field to the right, type the GREP ^die.*?$ – this will look for any word that begins with die. The destination should Map or rename, and the destination color name will be Dieline, with a CMYK value of 100% magenta, overprint on, and applied to Spot color is used. The checkbox should be checked on for ignore upper/lower case. Once OK’d from the bottom right hand corner, the fixup can then be activated using the Fix button on the bottom right of the Prepress dialog.

The fixup has worked – all of the colours have been mapped to the one color with the correct name and color value. An added bonus is that the color is set to overprint so that the color beneath won’t knock out.

Other applications

In this instance, the fixup has been used to fix a one-off issue concerning an incorrectly named spot color. But this fixup can be added to a larger workflow so that artwork from external sources can be cleansed for a workflow. See this article for more information (https://colecandoo.com/2019/02/24/droplet-like-its-hot/)

This particular fixup is also used to fix artwork that – while being set in the right color and name – did not have an overprint applied to the color. This fixup will correct this issue.

Add a “Night” mode to InDesign

In the same way that different political or religious views can polarise a group of people, so can one specific InDesign feature: Light or Dark interface.

Introduced into InDesign CC in 2013, this change brought InDesign in line with other Creative Cloud products that had a dark interface. That said, I was not a fan and chose to remain a user of the light interface.

Many years later and Apple released the macOS Mojave with its Dynamic Desktop and Dark mode. The Dynamic Desktop feature shows a bright desktop during daylight hours and a dark desktop during the dark hours. In addition, popular apps also followed suit allowing users to switch from the usual view to a “night mode”.

In addition, I have found myself working late into the night on projects, and have found that a darker interface during these hours is easier on my eyes. That said, I still like to use a light interface when working in daylight hours.

With this in mind, I wondered if it was possible to create an InDesign startup script that – upon performing a common task such as opening a file – would check the time of day and if it was beyond a certain time of the day, would invoke the dark interface… and it was.

I’ve now added this script to the site and it can be downloaded from here or the scripts/download pages. As this is a startup script, it has to be added to the Startup Scripts folder (see Ole Kvern’s excellent instructions for doing so here).

The script can also be modified to suit by going into any text editor such as textedit or notepad and editing the following lines of the script:

if (hours <= 7 || hours >= 18)

This indicates the hours of the day. In the script, 7 = 7:00 am, and 18 = 6:00 pm.

app.generalPreferences.uiBrightnessPreference = 0.0;

This refers to how dark the interface should be. 0.0 is totally dark, 1.0 is bright, but values from 0.1-0.9 can be used as well.

app.generalPreferences.pasteboardColorPreference = 1; 

This refers to the color of the pasteboard. The number 1 will match the pasteboard color to the interface, whereas 0 will leave the pasteboard white.

So technically it’s not a night-mode per se, but for those who like the light interface until the night-time hours, this script may be something to consider.

Housekeeping Scripts

You finally have an approval on that print project you’ve been working on for the last few months. All that’s left to do is make a PDF for the printer and be done with it, right?

Nope. It’s time to do some housekeeping on the file. Let me use this metaphor, once you’ve made dinner, you don’t leave your dirty pots and pans in the sink, do you?

It’s time to do some housekeeping, and in this episode of “must haves” on the Colecandoo Youtube channel, we’ll look at several scripts to keep your files nice and tidy.

Disclaimer

One word of caution with any of the scripts shown in the video. They are all destructive in nature. That is, they intentionally remove items from a document. Make sure you save your work prior to running these scripts, just in case they have a catastrophic impact on your artwork. I’m showing these scripts for educational purposes only, this is not a tutorial on how to use these scripts.

Images and Frames

Cleanup Pasteboard

The first script removes items from the pasteboard. Run the script and select the distance from the trim edge and importantly whether threaded text on the pasteboard should be removed.

I can hear some of you now saying “but what if I’ve left important notes on the pasteboard for the next person who works on the artwork”? Well, either don’t use this script, or put your notes on after you’ve run this script.

Empty Frame Remover

This script removes any purely empty frames, that is no fill or stroke that have no special settings applied such as text wrap or text on a path. Once run, it scans the document and removes all of these empty frames.

Trista DPI

The next script resamples all images over a given resolution to a more appropriate resolution. It’s great for projects such as yearbooks where the resolution of images is often far greater than it needs to be.

Now, I was in two minds to whether I show this script or not. Out of the scripts being shown in this video, this is both the most powerful and potentially most destructive of them. Ultimately, read the instructions before using this script, and make sure you have access to backups in case things go wrong.

Colour

Next, let’s address some colour issues that may have come about from selecting registration by mistake, or left-over swatches from a Microsoft Word import.

Unlike many scripts I’ve shown previously, most of these scripts are buried in forum posts, so it’s a matter of reading the post, finding the script, copying and pasting into a text editor and saving as a .jsx file.

It’s worth noting that all of these scripts only affect colours generated within InDesign, so won’t fix colour issues in links such as PDFs or photoshop files.

Add unnamed colours

Let’s start off with this easy one-line script that adds all unnamed colours to the swatches palette. True, it’s just as easy to select this from the swatches menu. Regardless how it’s run, this should be the first step to cleaning up the swatches. You can cut and paste it from below:

app.menuActions.item("$ID/Add All Unnamed Colors").invoke();

Reduce Colors

This script launches a prompt that allows you to search for colours that are a given percentage different from each other and merge them to the swatch that appears higher in the swatches panel.

If you’re using a special knockout black swatch and don’t want it to become the default black, perhaps make it a spot colour while running these scripts.

I explain the differences between these colours in more depth in Episode 14.

Registration Fix

This script converts all registration colour applied by InDesign to its respective tint of Black.

RGB/LAB GREY swatches to Shades of Black

I’ve written a script that converts RGB and LAB values that appear as shades of grey to equivalent shades of Black, while leaving other swatches alone to be dealt with by another script.

RGB/LAB swatches to CMYK

There’s another RGB/LAB converter, though this script converts all RGB/LAB swatches to CMYK values.

Faux Black fixers

There are two scripts that can take faux black values and convert them either to 100% black or rich black. The faux black is determined by CMYK values beyond certain percentages. In this case, any swatch that is over 70 Cyan, 60 Magenta, 60 Yellow and 90 Black will be converted to either 100% black or rich black. You can dig into the script if you like, and redefine what constitutes a rich black or faux black.

Remove unused swatches

This will remove any swatches not used in the artwork.

Styles, Master Pages and Layers

Let’s make sure that we only have the necessary styles, master pages and layers that are required for the artwork.

Remove unused masters

This script removes any master pages that have not been used in the artwork.

Remove unused layers

Next is this script that removes any layers that contain no artwork.

Remove unused styles and groups

This is a series of scripts that removes any styles not used in the artwork, as well as unnecessary style groups that may have been left, whether deep in folders or not. In the video it is combined into one “catch-all” script for convenience, but it is the work of many authors, so it’s not right for me to host it. Links to the originals can be found here, here, here, here and here.

Delete guides

Lastly, this script removes all guidelines in a document. I can see that there would be some use for guidelines to remain in a document, but felt it was worth demonstrating.

Preflight

To be sure that the artwork is completely free of issues, we want to make sure that there are no prepress issues. To make sure that the artist complied with the preflight that was associated with the document, there’s the preflight enforcer.

As shown on the Colecandoo Youtube channel before, I’ve prepared two scripts that will either warn or prevent a user from printing or exporting to PDF until all preflight issues are resolved.

So there you have it, over ten scripts that will help make housekeeping of InDesign files a lot easier. If there’s any that I’ve missed or you feel would be worthy of a future video, let me know via my contact page.

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