hi does anyone here know what this effect would be called in vintage ads? Would I use an overlay to recreate this, a filter, or a design asset of some sort ?
Thanks
It is just a by-product of Moiré correction.
Printing - CMYK dots make a nice pattern. You can do this in PhotoShop but if it’s going to be printed that will add another set of dots so be careful. Should be OK on a website.
There may be other ways, but one way to do this in Photoshop is to go to Filter > Pixelate > Color halftone…
If you want a more subtle effect, apply the filter to a duplicate layer and reduce the opacity.
Again, there may be other ways, but that’s probably how I’d do it.
As StudioMonkey pointed out, proceed with caution if the end result will be printed.
Are you new at this? There no shame in that, of course, but your question comes across like a mechanic wondering what the oily stuff is that he found in an engine.
The pattern you’re seeing isn’t an effect — they’re typical 4-color halftone rosettes. Grab a loop (magnifying glass) and look at anything printed using 4-color offset printing, like most magazines, and you’ll much see the same thing. It’s a normal artifact from offset printing. It’s possible in your example, though, that the scan has been run through a descreening filter algorithm to hide the halftone pattern a bit.
Given that this looks like something out of the '60s or early '70s, it likely would have been printed letterpress rather than offset. Letterpress printing used a coarser screen than what’s used in offset today, which makes the halftone dots more apparent.
If you want to simulate color halftone rosettes in Photoshop for some reason, here’s a link to a video. As others have pointed out, if you end up printing something with simulated rosettes, you’ll end up with what amounts to a doubled-up set of halftone dots and a very distracting moiré pattern.
Unless you print it digitally with a machine output of over 300DPI (dots per inch)
We print faked patterns like this all the time, or sometimes even standard scans that include the rosettes, sometimes enlarged well beyond what anyone could deem attractive. But most often standard photo sized prints. Inkjet prints couldn’t care less.
But standard press printing with plates, yeah, moires. When we order the real-deal porcelain (not the cheap dye transfer stuff,) they still use halftone screens and nothing is more disheartening than to have an image moire in a process that is basically image-made-of-glass and lasts 40+ years.