custom dither/halftone effect

[super gnu]

ive got to recreate some packaging. i have the labels as images, however the actual product has the labels prited on metal, and it uses a "dry offset" printing method. the final colours have been achieved by a kind of halftone effect. however the constituent colours are not cmyk, they are various light/dark versions of the final colour.

so, the halftone effect in photoshop is out, i think..

anyone have experience in creating this kind of effect from a normal texture?

[pokoy]

There's a 3rd party map (works in Vray) called Patchwork, available on maxplugins.de
You could use this map using dots in tile mode in the map to achieve the effect for each color component and then mix them in a composite map. Typically, the dot structure on the offset plates for the unique colors (usually C, M, Y, K) are rotated by 15°, for example C-0°, M-15°, Y, 30° etc. That would be the general setup, but you would have to figure out which and how many original colors were used for printing. However, an important limitation would be that the intensity of the color (0-100% greyscale) would need to affect the dot size... the map doesn't support this. Maybe the new OSL halftone/toon map in 2020 can help here.

Another way would be to use PS. Instead of the hafltone filter, try this: convert a color channel to greyscale and then to bitmap and choose halftone from the menu, it'll give you some options for the halftone type and the rotation. You should use pretty high dpi when converting to bitmap: the resolution used for the raster dots in real-world print is 2400 dpi mostly, the typical raster resolution is 150lpi. When you do this for each of the channels and choose the correct colors and composite mode in Max you should be able to get something usable. Expect some moiree in the render, though, I guess this is inevitable.