This is the only way to make Photoshop mimic 100K overprint. InDesign does this by default.
You really want black text to overprint the other inks, not knock them out which will result in registration problems, and illegible text.
Thanks for Your help
We are glad that you got it correct.
Thanks for the update.
When the type color is not black, another technique is used to compensate for possible misregister during printing.
I simulated the technique -- overdone here, so that it's method is easy to see.
In the top pair, blue on yellow, as shown on the left, since transparent inks are used, blue on yellow would yield a green,
In the blue on yellow. the right, the type was printed without distortion. In the yellow, the type was knocked out and shrunk. In production, distortion is approximately .002". Look closely and you will see the resulting overlap.
In the bottom pair, yellow and blue, transparent inks would produce something similar what is shown on the left.
On its right, undistorted type was knocked out of the blue, and the yellow was spread to overlap the knockout.
Note that we always distort the lighter color of the pair.
Remember: the samples shown here are grossly overdone so that you can see the effect.