Multiple linescreens

[Suz_S_]

How do you assign multiple line screens to multiple objects in Illustrator?

[Monika Gause]

You can apply patterns. But maybe you are referring to just the output? Can you be a bit more preicse?

[Suz_S_]

Yes, I'm actually looking at output to a printing plate. 

[Monika Gause]

You can't do that in Illustrator. Maybe Acrobat (or Prepress plugins for Acrobat) offers this kind of functionality.

You can change the screening in the print dialog box, but not per object.

[Suz_S_]

Okay, that was what I was finding, but I thought maybe I was missing something. Or, maybe I wasn't looking in the correct place. 

There isn't anyway to set line-screens and angles in Acrobat by graphic item. I have tried using several plug-ins. Freehand would let you do this to each graphic item. You could then distill those into a PDF or Postscript file. The advanced settings lets you preserve those settings.

You can't add them to the files after, that I can find.

[Mario Arizmendi]

You can't do that in Illustrator, the way that I do it is in photoshop, I screen the desire elements the way that I want and then place it again in AI for final output.

The settings depend on what exactly you want to do and the final workflow, What Rip, output Resolution, ETC

so if you can show your artwork and workflow maybe will be easier to show you a workaround

[Suz_S_]

The creating of screens in Photoshop works, but it is taking ten times longer to use this work-a-round. What use to take me minutes in Freehand, now takes several hours to do in Photoshop, and then build in Illustrator. I was hoping there was a setting I wasn't finding in Illustrator. I was told it doesn't exist by Adobe. Thanks for all the replies though.

[Conrad C]

FreeHand let you control halftone screens at the object level, by sending PostScript halftone code to imagesetters, during the bygone age when early imagesetters were very literal about halftone screens. If you entered 133 lpi at 45 degrees for a plate, that's what you got. But when the digital CMYK screens were overlaid, a common problem then were distracting moiré patterns. The moiré patterns were reduced by applying irrational screening, where imagesetters do not apply exactly the frequency and angle you specify, but other values calculated to get you the result you want with less visible moiré patterns. And they can also vary the shape and size of the cells to get there. But all of those adjustments meant you no longer had direct PostScript control over the halftone values that actually came out of the imagesetter. That was when halftone controls at the object level started to disappear, because then there was no point to it.

According to PrintWiki, where you can read about digital halftone screening in more detail, moiré patterns were finally eliminated through supercell screening. This gets even farther from how traditional halftone screening is done.

That’s why building halftone screen effects for design reasons is now done as a graphic pattern or plug-in type of effect, not by trying to directly address the imagesetter hardware like FreeHand did.

I used to do tech support for FreeHand, at Aldus.

[Ton Frederiks]

Illustrator had similar capabilities, you could use a file (Illustrator Riders file) and later a plug-in to insert PostScript code to modify the screening into a print file.

I used to do tech support for Illustrator and Photoshop at Adobe (in the early nineties) 🙂

[Mario Arizmendi]

Tom

this sounds interesting, so can you tell me what exactly is an "Illustrator riders file" and what plugin you are referring to, please.  

Thanks in advance

[Conrad C]

The Riders file! Wow, that takes me down Memory Lane.

I remember now...Illustrator and FreeHand could both do it, the difference was FreeHand put a GUI on it.

@Mario_Arizmendi — Illustrator stopped supporting the Riders file many years ago. I think one reason was that much of the custom PostScript you would use in there, like custom halftoning, only really worked on PostScript Level 1, which I don’t think was used much by the 2000s. Ton should correct me if I’m wrong on any of that. But if you want to read some examples of how it worked, a web search turned up this page:

Halftones on PostScript printers

[Ton Frederiks]

It should have worked on PostScript level 2 devices (level 2 was introduced in 1991).

Mario, the Riders file only worked when printing to PostScript printers, you could not save the result as a screened file.

There is not too much to find about it, this is one result:

https://books.google.nl/books?id=O_JdDwAAQBAJ&pg=PA85&lpg=PA85&dq=Illustrator+Riders+file&source=bl&...

[Mario Arizmendi]

Wow, thanks Conrad an Tom

This is so old, I am Illustrator user since 3.0 version and never heard about this before...

As I am not a code man, I think this is not easy for me to get into.

I will stay doing different screenings on a file in photoshop for now 🙂

I have tried the Phantasm Plugin to do halftones but not much happy with the results

[Suz_S_]

So generally the above is true, for most things created in digital art today. For most things it is better to let the machine do the work. Not in this instance. 

I am using this process to create security features. Which are still very much in demand. In this, Freehand rocks.

I also still have customers who try to create additional colors, without adding inks to printed materials. This the digital systems today does quite well, and can be controlled at the output stage with screen angles & overprints. No double burning necessary. For that I am grateful. Thanks