ID Preflight captures an obscure Illustrator error

I’m not saying this is wrong, but InDesign’s new Preflight feature works a little more advanced than I thought it would.

I have an ID document with the Preflight setting for images to reject any color images with resolution under 250 ppi.

I placed an Illustrator file with a glow into the ID file. Now glows automatically create rasters. So I made sure the Document Effects Raster setting in Illustrator was set to 300 ppi.

When I placed the file in InDesign I scaled it up a bit. Now, I’ve been scaling vector files for over 21 years! Never had a problem! After all, vector files are resolution independent.

So I was surprised when InDesign’s Preflight panel reported that the Illustrator file had too low a resolution. That didn’t make sense.

And indeed, the Links panel info did not show any wrong resolution at all because InDesign’s Links panel doesn’t show resolution for PDF files which is what the Illustrator document is as far as ID is concerned.

Fortunately, I knew about the glow effect. So I opened the Illustrator file and scaled it up to about the same size as it appeared in the ID file.

Then I updated the Illustrator link.

Preflight deleted the error.

It’s an obscure situation, but could cause confusion.

Illustrator doesn’t resample the raster effect when it is scaled up in the ID file. Rather, the raster effect is scaled to create an effective ppi that is lower than the raster effect setting in Illustrator.

So you have to make sure that Illustrator images with glows and other raster effects (shadows, feathers, etc.) aren’t scaled up in ID to create a low resolution effect.

Comments (18)

Commenting is easier and faster when you're logged in!

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Name *

Email *

Website

Loading comments...