my client is printing a newsletter and they are using only two spot colors and neither is black. The newsletter contains photos so what are my options? Can I make the photos gray-scale and then use one of the spot colors as a screen?

I'm using InDesign to create the template and can also use Photoshop and Illustrator.

Any thoughts? Thanks so much!

  • Take a look at this post: graphicdesign.stackexchange.com/questions/77703/… I will try to update this using diferent colors than black.
    – Rafael
    Commented Aug 23, 2017 at 17:09
  • You do understand that spot colours are just pre-mixed inks, toners, etc. and as such you may (and can) do what you wish to achieve the desired effect using solids (with or without posterizing) or halftones?
    – Stan
    Commented Aug 23, 2017 at 17:36
  • Hi. Take a look at: graphicdesign.stackexchange.com/a/84485/84899 where I give some tips on making two-color images.
    – Wolff
    Commented Aug 23, 2017 at 17:57

3 Answers 3


Yes, you can just grab one grayscale photo and make it into a monotone.

But My approach would be taking advantage of your palette.

I wrote a previous post using only black and a color: Preparing design for duotone printing?

And here is an update using colors other than black.

These two cases were made using the same technique I explain in that post, separating the channels and adjusting the curves. I used Red channel and Blue because my main objective was to have a "skin tone", not an exact match, but at the same time having some colors to play arround.

First of all, choose a style you want to achieve. And choose a dark color. The first objective of this color is to print the main text at 100%.

Then you have different options, choosing a similar color, a more happy and saturated one, so your images have more life.

enter image description here

Or you can use for example a "complementary" color, this way you can mix them and have a darker and more neutral one.

enter image description here

Do not choose two light colors. If you need a light one for something specific, like a logo, see if you can choose a darker one and use it at 50%.

I was exploring some method to simulate a lighter Pantone using a darker one. Here is one. This will not always work because as these colors changes, also the saturation (and hue) changes.

  1. Choose your light color and measure it with an HSB or HSL color model (I am using Corel Draw here)

  2. If you can, push the saturation all the way up, this is at 100%

  3. Now measure that new color as a Spot color (Pantone)

  4. Now you can use this at a lower percentage.

enter image description here

It is not perfect but it surely helps.

Now you have an additional color to play around!

enter image description here

(Original images by pexels.com)


There are several options here, all of them require Photoshop.

These two options will create an image in a 2 color format based on 2 Spots, but not "true" Spot file.

  1. Image > Adjustments > Gradient Map: Select a gradient with your two colours on opposite ends. This will map the gradient to the image, but it takes some playing with and I find it can create some odd looking effects if done improperly. This will ensure 2 colour images however.

  1. Image > Mode > Indexed Color: Select "Custom" under Palette and define the two colours that you will be using. You can drag and select multiple pallette squares to make them all one colour in case there are too many to do individually. Play with the options, including transparency and dither, and you can end up with an image that is in your 2 colour format and often looks a bit more normal than the Gradient Map option.

To create a "true" Spot file, the process is a bit more involved:

  • Go to the "Channels" tab beside layers and create two new channels
  • Double click each channel and choose "Color Indicates: Spot Color", you can choose the color at this point or afterwards
  • Mark in white on the individual channels where you want that color to show. A very easy way to do this is to Ctrl + Click a different color channel (RGB is a good one, since it has a nice balance) and then fill White on the resulting selection for your new spot channels
  • Delete or hide the channels you don't want (non-spot)
  • Save the file as a DCS 2.0 or PDF format to preserve the spot channels

This process is described in more detail here: https://helpx.adobe.com/photoshop/using/printing-spot-colors.html

I hope these help somewhat! Not having black as one of your available colours is a very tricky situation to be put in, good luck!

  • Are you certain these methods work for spot colors?
    – Scott
    Commented Aug 23, 2017 at 16:51
  • I've reviewed the options, and it seems that the Hue/Saturation will not be viable as it does not allow Pantone Spot as a base. I'm updating the answer to reflect this, as well as explain the concept of Color Channels.
    – KoldBane
    Commented Aug 23, 2017 at 17:13
  • I don't believe the Gradient Map nor the index mode allow for spot colors to separate properly either. You may be able to choose a spot color when using these methods, but everything is still output as CMYK, not spot.
    – Scott
    Commented Aug 23, 2017 at 17:21
  • Yes, I've updated my answer to reflect that.
    – KoldBane
    Commented Aug 23, 2017 at 17:22
  • I followed the link and I converted the photo to a duotone and used the two spot colors. I will see what the printer says. Thanks for the help. Commented Aug 23, 2017 at 18:06

For inDesign, you can place a greyscale TIFF and then "tint" or "color" the image using swatches. You can set the box color and the grey level swatches separately depending on the selection mode you are in.

This will work for one-color images for sure and may work for 2-color, depending on your desired look.

see also: Make the same grayscale image appear in different colours in InDesign

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