Ai 2018 — Problem with Jagged Edges

[tomaszkkk]

Dear Community,

if you check attached screenshots, you see jagged edge of the shape on the purple background. The same shape is not aliased on the yellow background. Does this have anything to do with the background colour (I've noticed that magentas and blues were causing this jagged-edge-effect) — or perhaps with the mode my Mac displays colours? Is there any way to avoid this bad-looking aliasing? I'd appreciate any suggestions and help.

Best regards,

Tomek

[Mohammad.Harb]

If you turn off preview on GPU ( cmd + E ) do you get a better result?

[tomaszkkk]

Unfortunately, I don't...

[Michael Bullo]

By default my version of Illustrator is giving me nicely anti-aliased lines. However, I was able to create a jagged line similar to yours by turning off the following settings in the Preferences…

• Preferences > General > Anti-aliased Artwork
• Preferences > Performance > GPU Performance

Are these options active within your Preferences?

The following is an excellent forum thread on anti-aliasing within Illustrator you might want to check out...

Type looks jagged/pixelated inside Illustrator

[tomaszkkk]

Yes, they're active. Thank you for the link to the forum thread, though.

[mark-heaps]

Hey Tomek,

what percentage are you viewing this at? Like as you zoom in or out does the aliasing get better or worse?

Also go under the View menu and try the various preview states to see if it alters the appearance quality.

[tomaszkkk]

Actually it was quite a huge zoom: ca 3000. Oddly enough 400% looks even worse. Check the screenshot below, please:

[Monika Gause]

Which document color mode is it?

How is the black color set up?

[tomaszkkk]

CMYK. Black: 0% — 0% — 0% — 100%

[Monika Gause]

The problem is with 100 K rendering in CMYK color mode. It will always get this grey edge on screen.

Since yellow is lighter than purple, it's not obvious in the other example.

You will always get some pixels on screen, because that's how monitors display artwork. Some angles of your strokes display it more obvious than others.

[tomaszkkk]

That's too bad. Anyway, thank you for the explanation.

[mark-heaps]

So the screenshot may be the element to test against here.

If you take that same start graphic, and use export to save out a PNG or JPEG with no compression. View it at 100% in a browser (force open in browser) does it look jagged?

Monica is likely correct here, this may be a display monitor issue of the vectors rendering for the video card.

[tomaszkkk]

Well... I did what you had advised and there's actually a difference between jpg and png in favour of the latter one. Png version appears to be pefectly antialiased (but the resolution of the png file has been set up to 600 ppi).

[tomaszkkk]

It looks like this:

[Monika Gause]

Is this a screenshot of the exported PNG or the exact PNG you exported?

Because it's an RGB image. And as I already wrote, the problem is in CMYK mode.

Also: is your issue only with the screen view? It's irrelevant for printing.

Or do you export to a CMYK raster image? Then please tell us about your workflow.

[tomaszkkk]

It's the exact PNG exported from Ai. I take the liberty of o attaching CMYK jpg (600 ppi), just in case.

The problem of printing has not occured yet, simply beacuse I did not have to print my Ai projects.

[Monika Gause]

This is how your CMYK PNG looks in Photoshop for me (about 150%):

If you don't need to print, then why use CMYK color mode and 100 K?

[tomaszkkk]

Good point. Looks like I shouldn't.