What is "100% K" and how do I set that up for my images?

[Mateomono]

Hi! 

I'm having a hard time understanding what this means and how to fix it:

"On some pages, the data is composed of CMYK, mainly barcodes or photos. For the books, a 1+1 (b/w) print is planned. The EAN should be in 100% K, as well as the images."

How do I change this? Does this also apply to vector graphics?

This is for a book project for print. 

Thank you!

[Eugene Tyson]

100% K means that it should be in 100% black ink only - no CMY only the K channel.

Here they both look the same on screen

but checking the Separations Preview panel Window>Output>Separations Preview

You can see that the 2nd only has more than just Black

 You can also setup a preflight check to find objects using CMY - ergo not meeting 100% k

 https://helpx.adobe.com/ie/indesign/using/preflighting-files-handoff.html

 And it will show you here in my proof concept fake barcode 

If you need anything else let us know 😄 

Hope it helps

[Mateomono]

@Eugene TysonThank you for this great explanation. How do I do this for images or PSD files?

[Mateomono]

@Eugene Tyson Also I cant seem to find this prefligh option on my end. Do I need to install it?

[Mateomono]

@Eugene Tyson Nevermind, I found it.  Sorry about that 

[Eugene Tyson]

It will work on images for PSD and other images too
Image looks BW

But turn off the Black and you see the other plates

The preflight profile also picks it up

   

Same with vector images

Looks black and white

But turn off the black chanell and you can see the CMY plates

Plus the profile also flags it.

 

[Mateomono]

@Eugene Tyson I see, but how do I convert it?

[Mike Witherell]

What software generated the barcodes?

[Mateomono]

@Mike Witherell Im not sure! But I have them as PSD files

[Dave Creamer of IDEAS]

I would save them as Bitmap-mode, LZW-compressed TIFF files. Less problems. 

[Mike Witherell]

Shapes like that should not be pixel-based PSD files. Since they are vector bar shapes, I was imagining that you would say they are from Illustrator (or at least generated and opened into Illustrator and saved as AI files).

If so, I would make (in Illustrator) an Illustrator *global* swatch that is 100K and apply that pure black to the fill of the vector bar shapes. Save as an AI file, and place into InDesign. This will ensure that the black barcodes stay 100% on the black plate.

[Mateomono]

@Mike WitherellOk, then I would need to ask for an SVG file. But how do I make these updates if it's an image that should only be 100% K?

[Robert at ID-Tasker]

@Mike WitherellOk, then I would need to ask for an SVG file. But how do I make these updates if it's an image that should only be 100% K?

By @Mateomono

If you get EAN code SVG file prepared CORRECTLY - it will be Black. 

If not - then you'll have to open it in Illustrator and apply 100% Black swatch / color and save as PDF. 

[Mateomono]

@Robert at ID-TaskerI only got a PNG for the QR codes. It sounds like I need to open it up in illustrator and edit it from there. 

But I'm still a bit confused—how do I ensure the images in my book are only 100% K? For vector files, it's clear, but not for images.

[Robert at ID-Tasker]

@Mateomono

PNG -> Photoshop.

Just use link I've provided and create a new Barcode. 

[Robert at ID-Tasker]

@Mateomono

Or if you don't have too many Barcodes - you can re-generate them using this website for free: 

https://barcode.tec-it.com/en 

[Eugene Tyson]

---

@Mateomono wrote:

@Mike WitherellOk, then I would need to ask for an SVG file. But how do I make these updates if it's an image that should only be 100% K?

---

AFAIK - SVG is RBG only - so a 100% black won't exist, even if you create it in CMYK - the only colour format it has is RGB, so it converts to RGB.

This is then converted back to a 4 colour Black. 

If it's vector, then use colour mode CMYK in Illustrator first then apply 100% black to the image/barcodes.

Then save as .ai file with PDF compatible turned on. 

[Mateomono]

@Eugene Tyson Thank you for your response, but I am a bit confused about how to do this with my QR codes as SVGs. Could you help me understand?

[Eugene Tyson]

Open the SVG in illustrator 

Save the file as .ai with PDF compatible

File>Document Colour Mode>CMYK

Change the colour to 100% black

Save the file

(you could record these actions in Illustrator to save time - then play the action for each file)

Going back to InDesign

Relink the .ai file in inDesign - you don't have to do 1 at a time

In Indesign - select all the SVG links in the Links panel - then use the Sub Menu to relink to file type, and choose .ai

As long as they are in the same folder. 

[Mateomono]

@Eugene TysonThank you for the amazing explanation. It's now all clear. It's still a bit unclear how I would convert an image (regular images) to be all black at 100k. How do I do that in Photoshop? I was under the impression it works when converting to grayscale, but I wasn't sure. 

[Robert at ID-Tasker]

@Mateomono

In Photoshop - you would've to convert your image to Grayscale and then play with threshold to make everything 100% K - or B/W - there is no need to keep it as CMYK with only one Channel - K - populated.

Other advantage of having it as Gray or B/W - you can easily "color" it - apply a different color. 

But, as already pointed out - bitmap isn't a good format for Barcodes - unless you'll make it B/W and at least 300ppi. 

[Eugene Tyson]

@Mateomono yes - if the images are not critical in colour and you're happy with the convert to grayscale - that will do it. It depends on the image really, if there's solid black areas of the photo then they might appear ok on screen but if not 100% black - it might be say 95% and could look a bit dark dark grey in print. 

You could do as @Mike Witherell suggested - and sorry if I misunderstood, yes they do say 1 + 1 but I interpreted this being 1 on front and 1 back, so 1 over 1, or print front and back. I know it's sometimes written as 1/1 or 1/0 etc. 

A blanket conversion to Grayscale if you're not too bothered would work too - you can do that in export to PDF from inDesign - or in acrobat directly.

That would save a lot of back and forth in converting all the images. 

What do you think? A more controlled way or just convert everything to grayscale and be happy with that method?

[Dave Creamer of IDEAS]

I've already posted the best format, but take your image (ideally, high resolution), convert to grayscale, then convert to bitmap mode using 50% threshold, save as LZW-compressed TIFF. This will be black only and the white areas will be transparent if you desire. The TIFF can be colored in InDesign if desired (as long as you have correct contrast between code and background). If you have a number of these, you can create a batch process in Photoshop.

[Mateomono]

@Eugene Tyson How can I do the steps you mentioned up here with a PNG file for my QR codes? 

[Dave Creamer of IDEAS]

Follow the steps I listed a few minutes ago. They should work fine.