The color values are clearly different.
My photoshop color space is linear.
For example, if you draw gray B (128,128,128) on gray A (128,128,128) in photoshop with overlay
The formula for photoshop is
1-2 * (1-0.5 (Gray A)) * (1-0.5 (Gray B))
The drawing result is
(128,128,128)
But
blackink drawing results
(119,119,119)
sample
https://15.gigafile.nu/0120-d41817fbd27 ... c7b6b5edd8The same is true for hard lights, which are the inverse of calculations for overlays.