Illustrator question

[GVP]

Greetings!
Although we don't use Illustrator much, occasionally we use it for bringing in customers files for modifying. We use the 'flatten transparency' method on those with linked files, but notice that often the images are broken up into lots of squares. My question is a) why? b) is there a way to fix it c) will it show up on any print?
First image shows 'unflattened', second after flattening.

 

[shoresigns]

a) Flattening transparency combines the transparent objects with whatever is underneath them, and to do that it has to slice up the results, usually based on where the overlaps are.
b) Sometimes if you drop the customer's PDF file into Photoshop you can extract the whole unsliced image and then save it, import into Illustrator and rebuild the file. That is generally only worth the effort if the file isn't very complex. Otherwise you need to just ask the customer to do the edits or send you an Illustrator/InDesign package.
c) No, it shouldn't show up on your print. The visible lines between the sliced images are an on-screen rendering issue due to antialiasing, but your printer will see them as butted up against each other with no gaps between. The exception might be if you export to a raster (TIFF or JPEG) for printing, then you should double check to make sure the lines are not visible in the file.

 

[JulieS]

I've found that the little white lines don't show up in the prints. But there can be other color problems that ONLY show up in the print when I flatten transparency if there are vector elements in the file (there are invisible boxes around these elements that slightly alter the color of whatever they're on top of when printed). I deal with this by opening the file in Photoshop & re-saving it before printing.

 

[timkaz227]

Greetings!
Although we don't use Illustrator much, occasionally we use it for bringing in customers files for modifying. We use the 'flatten transparency' method on those with linked files, but notice that often the images are broken up into lots of squares. My question is a) why? b) is there a way to fix it c) will it show up on any print?
First image shows 'unflattened', second after flattening.
View attachment 129865 View attachment 129866

Is there a reason you are flattening the image? I will sometimes flatten an image if I'm having an issue printing. But only if I find it necessary.

 

[GVP]

Is there a reason you are flattening the image? I will sometimes flatten an image if I'm having an issue printing. But only if I find it necessary.

When we need to manipulate part of the page, e.g. modify some text.

 

[Bobby H]

If the artwork is a native Adobe Illustrator .AI file there should be no sliced up artwork, bounding boxes and other extraneous trash -at least not when you're opening the .AI file in Adobe Illustrator. Normally the boxes and sliced artwork comes from placed PDF files, with the PDF being the variety where Illustrator editing capability was not preserved when the PDF was generated.

If you're trying to import late version Adobe Illustrator artwork into other applications (such as CorelDRAW) and the Illustrator artwork has all sorts of complex fill effects (like gradients with varying levels of transparency) or any other unique effects that are dependent on Illustrator then the artwork may come into the application with all sorts of very wacky, unpredictable results. Some fills may be rendered as power-clipped raster images. Some fills may still be vector, but with the colors and transparency levels shifted all over the place.

It's easy for CorelDRAW and Adobe Illustrator to accurately trade vector artwork back and forth when there are no "live" application-dependent effects applied to the artwork and the fills solid colors or simple gradients. The user is asking for trouble when things start to get complex. Corel and Adobe aren't nice to each other in that regard.

 

[Lea Marc]

When we need to manipulate part of the page, e.g. modify some text.

If you need to manipulate text, could you not edit the file in Acrobat Pro instead saving you bringing it into Illustrator?

We get those white lines too and whenever I have a problem printing pdfs it's usually because of effects such as gradients. Opening the file in Photoshop and saving as a tiff usually fixes that. Although it bitmaps the image the difference in quality is so minuscule that you won't see it on a sign with the naked eye, especially at the distance they are viewed at.