I guess I'm a packages sort of kid, for tonight anyway.
The backstory here is that I recently noticed that the printing on product packaging is a lot more sophisticated than it used to be.
It used to be that if I saw a photograph on a mass-produced piece of paper, it was a very safe bet that when I looked close with a magnifying glass I would see a classic CMYK screened halftone, and nothing else.
Turns out, that's no longer the case. What I'm seeing now is typically 6 color printing, sometimes more, with a mix of halftoned CMYK, hard-edged vector mode CMYK, and a couple of other custom colors, which may themselves be printed in some combination of vector mode and halftones.
This hurt my head for a while, because I was having trouble imagining what sort of process was producing the printing plates. Finally it occurred to me that with high resolution photolithography and digital layout programs, the plates can easily be made with any pattern at all on them. The graphics guys can mix halftone screens with vector graphics at will, on the same plate, and in fact the halftone screens don't even have to be regular grids any more. I'm embarrassed by how long it took me to figure this out, but at least my head doesn't hurt any more.
Here are some examples.
To begin, the label on a package of popcorn: all halftoned with a regular grid, except for the logo which is vector mode.

I wondered if the logo was done with red ink, but no, on closer inspection it turns out to be just magenta and yellow from the CMYK inks, laid down in as solid layers with a smooth outline. They're not perfectly registered, so a closeup shows magenta and yellow halos on a red region, and in places there are islands of yellow where there are holes in the magenta.


However, elsewhere on the package other colors are used. For this package, the standard CMYK set is augmented with tan and gray.

The tan and gray are used for lettering. Here is a section of the package showing tan and gray text in vector mode, next to a photograph that is mostly screened, except for the product logo on the cap, which has obviously been pasted in as a vector graphic. What fun!

At least all of the above are regular grid screens. That seems to be the most common approach, but it's not universal.
Here for example is a bit of the label from a can of Hunts tomato paste. This label is just CMYK, as far as I can see, or maybe there's a dark yellow added in as a process color, but in any case the halftone screen is randomly positioned dots. Very clever!

I hope you find this interesting, or at least colorful.
Merry Christmas!
--Rik