Replicate InDesign duo-tone in Photoshop

Question

Hi First question here!

I've inherited a design from a previous designer which utilises a grayscale image which is placed in InDesign as grayscale then coloured as cyan and the container coloured as yellow (0,10,100,0). What it produces seemingly uses cyan as black and yellow as white. As you can see here:

The closest I've got is two layers of monotone with multiply effect. The colours are inverted. It's pretty close but not exactly the same.

I would do all the images in indesign if I could except the client has asked for photoshop droplets so that they can chose their images at a later date.

Thanks for having a look guys.

Answer 1

It is possible to reach that result from Duotone by modifying the Levels Curve of each ink.

Image from unsplash.com

Cyan = midtones and shadows

Yellow = highlights

Click on the cyan ink levels graph to modify midtones and shadows levels, on the example 100% of cyan ink at the position 60 (midtones) and 100 (shadows) of levels curve and 0% at 0 (highlights):

Click on the yellow ink levels graph to modify highlights levels, on the example 100% of yellow ink at the position 0/10 (highlights) and 0% from the position 20 to 100 (midtones and shadows):

Result

Answer 2

Another way to do this, essentially the same way that inDesign does it: a color overlay with the greyscale image as a mask.

Below I made two layers, each flood-filled black. I added a color overlay to each layer with the color chosen being the desired swatch color.

I then added a layer mask to the top layer, switched to the channels palette and then pasted the greyscale image into the layer mask channel.

Answer 3

To replicate the effect exactly, you're very close. This is the procedure I came up with to mimic the InDesign results.

Assuming you are working on a grayscale image:

1. Get the channel data
   1. Open the Channels Panel
   2. Click the gray channel
   3. Select All
   4. Cut the image data (make sure your background color is white)
2. Convert the blank image to CMYK
3. Add a new solid color fill layer
   1. Click Layer > New Fill Layer > Solid Color...
   2. Set the color of this layer to <100,0,0,0>
4. Paste the image data into the channel mask
   1. Make sure the color fill layer is selected
   2. Open the channels panel
   3. Click the Color fill mask to select it, then click the eye to make it visible
   4. Paste the image (everything will look wrong for the moment, that's ok)
   5. Click the eye and click CMYK to select all the normal channels
5. Create the yellow layer
   1. Return to the layers panel
   2. Right click your color fill layer and choose duplicate layer
   3. Double click the color on the bottom layer and set it to <0,10,100,0>
6. Finalize the blue layer
   1. Click on the mask of the blue color layer
   2. Select Image > Adjustments > Invert
   3. Change the blend mode to multiply.

This could be recorded into an action fairly easily so you can batch process all the images.