Using placed Illustrator file as clipping mask in InDesign

Question

I'm having an issue working out how to create a clipping mask with placed (not copy and pasted) illustrator artwork.

I have an icon set that I manage in illustrator. I create an artboard per icon and then place individual icons into InDesign via the 'place... > show import options' to select the artboard specific to the icon I want. I have a single layer enabled on the placed artboard which is a simple shape layer, black fill, no outlines, simplified as much as possible (all strokes outlined beforehand in illustrator and 'unionized').

The trouble I am having is applying colour plus blending modes to the icon. My current solution is to enable an inner-glow big enough that it acts in a similar way to a 'colour overlay' layer in Photoshop, but it feels a bit of a hack. Plus, it doesn't allow me to zero the opacity of the artwork if I want to apply a blend mode to the colour overlay for example.

Is there a way to do this? I know I can create an inverse of the desire effect by:

1. Grouping the placed icon with a filled rectangle set to the desired colour/blend mode
2. Arrange the filled rect behind the placed icon
3. Setting the icon opacity to 0%
4. Setting the containing group to 'knockout group'

I would rather not simply copy and paste the artwork from illustrator as the icons are being modified frequently so it's a much smoother workflow to simply update links.

I've tried to set the layer in Illustrator to a clipping mask but couldn't seem to get this working. I feel I must be missing something simple but googling is bringing up nothing specific.

Edit: Since posting I've tried adding an additional step to the 'knockout group' method described above where I have an additional layer in my illustrator source file which includes an inverse version of the icon. I then follow the steps labelled above.

This works, but has the issue that the icons render badly (aliasing) whilst editing in InDesign, and therefore need to be exported to PDF prior to seeing the final effect. This slows down my workflow too much to make it usable.

Also, as requested I've included:

1. An example of the icons I wish to colourise and blend, laid out on their source Illustrator artboards.
2. An example of the inversed icons in illustrator
3. An example of the two methods I've used in InDesign. The left icon colourised using 'inner glow' method and the right icon colourised using 'knockout group' method with a white tint layer set to overlay blend. You can see the poor rendering/aliasing.

Answer 1

In Illustrator:

• Create a new swatch for the icon's fill.
• Set Color Mode to Spot Color.
• Give it a good name (like "Icon color 1")
• Make it black if you like.
• Save your file.

In InDesign:

• Update the link.
• Now, your custom spot color appears as a swatch.
• Create a new swatch. This is the color you want your icon to have in the end.
• Set Color Type to Spot.
• Set Color Mode to the mode you prefer (RGB, CMYK or a Pantone color if that is what you need).
• In the Swatches panel menu, choose Ink Manager.
• Select the color you made in Illustrator and set Ink Alias to the new swatch you just made in InDesign.

Now you have mapped the placeholder color from Illustrator to a dynamic swatch in InDesign. You can make several colors this way to have control of the whole color scheme of the icons.

Remember: You can alter the color as you like, but beware that your new color is a spot color and now has its own channel. If you are not using Pantone colors that is probably not what you want. In that case, make sure to check All Spots to Process in Ink Manager.