Using a smartphone as a loupe

Part of my work as a prepress operator requires looking at printed material under magnification, usually a loupe. This is done for a variety of reasons, such as:

  • Determining if a previous print was printed in full colour process or spot colour;
  • Assessing the effectiveness of trapping;
  • Checking if print is aligned in register;
  • Determining the dot structure of a printed product (was it stochastic or halftone; and if it was halftone, was the dot shape round, Euclidean or other);
  • Attempting to determine the value of a colour breakdown;
  • Confirming that barcode width reduction appropriately compensates for ink gain on a printed barcode.

In previous posts on Colecandoo, I’ve shown several photos taken using my digital microscope, such as this image that was used to illustrate the misregistration of a varnish compared to the ink underneath.

The digital microscope is certainly useful for checking details not immediately obvious with a loupe such as the barcode example, but for most magnifying tasks, a loupe works just fine.

Isn’t there a smartphone app for this?  

Yes and no. There are specific smartphone apps I will use for prepress work, such as:

  • What the Font – great for identifying fonts when I’m far away from my laptop;
  • Measure – when a tape measure is unavailable and centimetre precision will do;
  • Adobe Scan – when I need to take in typeset material when I’m not near my flatbed scanner; or if a customer’s original can’t be taken apart to fit on a flatbed scanner.
  • Touch Portal – when I need extra buttons for my laptop – an equivalent would be elgato’ streamdeck.

Many smartphones now feature macro lenses that have comparable zoom to a loupe, but require the phone to be held the correct distance away from the subject and to have a steady hand or a rig established for the purpose.

Enter smartphone lenses

I’ve recently invested in a macro lens for my smartphone. Since using it at work, it has been quite useful – to the point where it inspired this article.

To demonstrate the difference of the smartphone macro lens to the default macro lens and the digital microscope, here is a comparison on a printed image.

For me at least, I can now safely stash my old loupe in the desk drawer and begin to use the macro lens as an alternative. Here are some reasons that I’ve made this decision:

It has several advantages over a conventional loupe:

  • Virtually no chromatic aberration
  • Others can see the image without me needing to share the loupe
  • Can share the footage live using screen sharing software so that the image isn’t just on the phone screen, but on a larger display; or take a photo and email to the client or file for later use.

There are also several advantages of this lens over iphone’s macro lens:

  • Higher magnification;
  • Stable to hold as the diffusion filter also acts as a rest;
  • As any Sandmarc lens is shipped with a case or clip to allow the lens to be mounted, it also provides the ability to change out lenses for other purposes

This also has advantage over the digital microscope

  • No wires;
  • Requires no additional power;
  • No additional “unitasker” software (serves one purpose alone)

However, the macro lens isn’t without it’s disadvantages:

  • Needs good lighting – a backlight would help tremendously;
  • Requires a case or clamp to fasten the lens, though with the Sandmarc lens that I purchased, this was provided upon purchase;
  • Requires additional software to access the individual lenses as the iphone’s default camera app will not allow this flexibility – software such as Adobe Lightroom is what I use, but this was on my phone anyway;
  • Not portable enough to become part of my everyday carryables such as car keys, phone, wallet etc. Is small enough to fit in a tiny bag that sits on my desk.

So while I now have a new tool in my prepress arsenal, I’d like to know what other apps or tools that people are using to assist them in their design or prepress tasks – feel free to comment below.

Finally, as a matter of full disclosure, this article is NOT sponsored by Adobe, Sandmarc, Apple or any other company mentioned in the article. If they would like to sponsor Colecandoo in the future, that may be something to explore, but this article is my own thoughts and opinions and the macro lens I purchased.

Page Size Lies

UPDATE 2021-10-08: Enfocus Pitstop has released an update that now resolves the error that was brought about by the update of Adobe Acrobat DC. However, I will leave the article posted for posterity.

Have you ever received a client’s InDesign file and sent it to PDF or print, only to measure the document and realise it is a different size to the one that was in InDesign’s document setup?

What could cause this issue to arise?

The page tool has been used

It is likely that at some stage between the initial creation of the file and receiving the file, at least one page size in the document has been changed using the page tool.

Preflight should tell me… right?

Well, that depends. If you are using either of InDesign’s default preflights (i.e. [Basic] or Digital Publishing) then preflight will not flag a warning.

I’ve discussed my frustrations with InDesign’s default preflights in Episode 19 over on the Colecandoo Youtube channel. However, if you are using a more comprehensive preflight such as the VIGC profiles, then this is detected as an issue:

More comprehensive preflights such as the VIGC profiles look for much more than InDesign’s default preflights e.g.:

As a side-note, the Document portion of the Preflight Profiles dialog box is also handy for authors who are making saddle stapled publications that must have page-counts in multiples of four (an issue I’ve faced several times) e.g.:

Or for larger offset publications where folded page signatures are likely to be prepared in minimum multiples of eight e.g.:

There are also scripts to highlight this

I’m working on a startup script that – upon export or print – should provide an alert dialog box warning that there are size discrepancies… but in the meantime there are some other scripts that work by providing alerts to a document’s page sizes, or a script hosted over on Kasyan Servetsky’s curated list that makes a list of the page sizes in a document (look for “Check all pages” once the link loads).

What I think would ultimately help everyone would be if the Document Setup window would change once page sizes in a document were no longer the same, such as this mockup e.g.:

PDF spreads from InDesign: radio button vs dropdown

When proofing PDFs of books to clients, it is often important that the client sees the proof as a series of left and right page spreads. PDFs made with any of InDesign’s default settings (these are the options in the Export Adobe PDF dialog box in the top dropdown field in square brackets) will show the PDF in Adobe Acrobat as it’s default view – single pages.

Adobe Acrobat does allow for pages to be presented in two-page appearance, but this is controlled by the user. If the user is unaware of this feature, then they will be viewing the PDF using Acrobat’s default single page view.

It is possible to change the view settings of a specific PDF while in Adobe Acrobat and this is done from the Properties option from the File menu.

The page viewing defaults of Acrobat itself can also be changed, but this will view any PDF that has not had its preferences changed when the PDF was made.

It is worth noting though that prior to 2015, the widely accepted method to prepare a PDF as readers spreads was to do this from InDesign’s Spreads radio button in the Export Adobe PDF dialog box.

While this does prepare what appears to be readers spreads, it does so with some disadvantages:

  • The centre spread line cannot be seen. This can be addressed by using the page border script from Indiscripts that applies a page border to all pages. Run this script prior to exporting the PDF to generate the page border and then export the PDF, then rerun the script to turn the border off.
  • The page count is incorrect. The folios will still appear to be correct within the PDF, but the page navigation itself will show the page count as half the number of original pages plus one (e.g. a 16pp file saved as spreads will now show up as 9pp in the PDF’s navigation).

However, from June 2015 it has been possible to set the default view options when exporting a PDF from InDesign for viewing in Adobe Acrobat.

This allows PDFs to contain the correct page count and to also show the page split between the spreads while still showing the pages as spreads.

Should be problem solved, right?

Unfortunately, no. Despite the dropdown now being available, there’s no ideal way to prepare readers spreads to suit all PDF readers or platforms.

  • Unless InDesign users read all of InDesign’s patch notes (maintained by James Wamser) or were otherwise made aware of this change, then normal habits would persist, and users would continue to prepare spreads using the spreads radio button.
  • If the dropdowns had been used, this only makes viewing the spreads possible in Adobe Acrobat (Reader or Pro), but unfortunately this software is no longer the preferred option for viewing PDFs. Besides Mozilla Firefox and Adobe Acrobat, most PDF readers only support single page view.
  • Even if Acrobat or Firefox are being used, users can still override the view either manually, or using Acrobat it can be done by default using accessibility in the preferences

So what can be done?

There are effectively four options:

First option is to prepare PDFs based on an audience using Acrobat only as their reader and use the dropdown option for spreads. If the PDF is exported from InDesign using a PDF/X standard, Acrobat will also show the PDF as it appears in InDesign’s overprint preview.

Second option is to prepare a PDF using the pre-2015 method of using the spreads button and the Indiscripts page border script.

Third option is to lobby the manufacturers of the non-Adobe PDF reader software to bring their software into line with the PDF specifications set out by Adobe itself (and while they are doing that, also update their readers to also accept form fields and commenting functions!).

Last option is to do nothing and leave the pages as single spreads… and that isn’t necessarily a bad option. If the PDF is being created for onscreen viewing only, and the viewer must see something that is intentionally spread over two pages such as an image that crosses over two pages, then single pages should be fine.

Last word

It is of note that people are not just consuming information on a single desktop monitor, but may have two or more monitors in which software windows are being juggled around; or on a mobile device that is more natural to be held in a portrait fashion. Social media apps such as TikTok and Instagram are designed for mobile devices to be held in a portrait orientation. It’s hard for me to admit, but left and right hand pages are just a legacy of printed books as their assembly creates this phenomenon. Unless there is a crossover between the two pages, a reader will usually read the content on one page, adjust their gaze and read another – their focus of vision can’t be on both pages at the same time.

Also, if the PDF is intended for print by a printing company, don’t provide them a PDF as readers spreads as they won’t be able to impose the pages for printing without breaking the PDF back into single pages.

Inklude (sic) Mixed Inks into Illustrator

A feature which is strangely absent from Adobe Illustrator (yet present in Adobe InDesign) is mixed inks. This gives the user the ability to make a new swatch based on percentiles of other swatches that can include spot colors, along with process colors.

InDesign’s mixed ink feature also allows groups of mixed ink colors to be made, based on how much of each ink should be in each swatch, and the increments they should differ by.

For pure spot color work, this can create colors that would otherwise require using blend modes such as multiply or darken to create similar colors. However, from a prepress standpoint, mixed inks have several advantages over applying blend modes to objects to achieve the same effect.

Embellishments

For digital devices that can apply inline varnishes, mixed inks make sense. In the following example, the headline requires a varnish

Usual way of doing this would be to create a second layer with an identical headline, but set to a Varnish spot color on another layer, with either a transparency effect such as darken or multiply applied; or overprint turned on from the attributes menu.

That’s fine if the position of the artwork is final, but if the design is in a state of flux, that requires moving the varnish to be in the same position as the type.

A solution is to use InDesign’s mixed ink to create a new mixed ink swatch. In this case, I’ll call it Varnished Headline, and give it 100% of the black and 100% of the varnish spot

This solution also applies to other common embellishments such as embosses, foils, raised varnishes, etc.

White Masks

When preparing label artwork for clear or metallic substrates, white masks have to be prepared so that the color art can appear correctly above the substrate. Take for example this logo to be printed over a silver background.

Again, by using mixed inks, it is possible to make a white mask that doesn’t require another layer, blend mode, and can move with the artwork. In this example, three colors would be created: the white mask; Red and a white mask; and Black and a white mask – the last two being mixed inks.

The art can then be recolored so that the red now uses the red mixed ink; the black now uses the black mixed ink; and the paper now uses the white mask ink.

Notice that the gold cup does not contain a white mask – that is because the gold color – when printed on a silver stock – will appear more like a gold foil.

Double-Hit Prints

On one or two spot colour jobs that have large areas of solid ink coverage, occasionally the same colour will be applied twice on the press as to hide any mechanical ghosting from the printing process.

In the above example, one plate would be for the solid color, and a second – though stippled plate – would be for the undercolor to hide the mechanical ghosting. This color can be set up using InDesign’s mixed inks.

But this is missing from Illustrator!

Despite the mixed ink feature being available in Adobe InDesign, it is notably absent from Adobe Illustrator. This is frustrating as artwork that usually requires the three solutions above is often prepared as Adobe Illustrator artwork, requiring old-school solution of layers and blend modes.

If you feel that this missing feature deserves to be in Adobe Illustrator, make sure to let the Illustrator Uservoice know!

%d bloggers like this: