A problem we often run into when converting AI to PSD is the file becomes flattened and no longer has editable layers in photoshop. It occurs when the PSD conversion engine hits a layer with an attribute setting called ‘Overprint fill’. It’s a rarely useful setting that in many cases can be turned off.
To verify it’s ok to disable, open the AI document and go to ‘View > Overprint Preview’, if anything changes visually you will need to speak to the designers (if you aren’t one) about suitable changing of the file. If it doesn’t, you may safely turn off Overprint fill. To do so Press Cmd+A (Ctrl+A for windows) to select every layer in the document. Go to the menu and select ‘Window > Attributes’. A small window will open up with the ‘Overprint fill’ setting.
Click the overprint fill checkbox a few times until it is blank. A notification prompt may appear, click ok if it does.
With the Overprint fill setting disabled, you will be able to export to a PSD with fully editable layers.
September 19th, 2007 at 23:18
Thanks so much for this tip. I think it worked although once you disable the overprint fill, click off the layer, and click back on it, it looks as though it has overprint fill selected again. However, I did not get the warning this time about layers being flattened. What I did run into was a warning about not being able to convert to PSD because of a 500 layer limit. Guess that is a different topic of discussion.
November 3rd, 2007 at 0:55
Overprint is a term relative to printing which helps to increase the density of blacks and avoid errors within the print process. This can be assigned by the creator or automatically assigned by the RIP. Without such settings there would be errors in print. During the print process 4 colours are used to create full colour images - Cyan, Magenta, Yellow and Black. Whenever a colour is applied over another colour the same shape is removed from the underlying colour so that it doesn’t affect the colour on top. As an example if we print a blue square and within that square we print a yellow circle the circle shape is removed from the blue square. If we didn’t remove the shape the yellow and blue would combine to give us a green circle. This process is known as Knockout. When we print black on top we often require the density of the black to be enhanced by using the underlying colour and therefore no knockout occurs, this process is known as overprint and the resulting black is referred to as a Rich Black.
For web there’s no need for such settings and as it’s an attribute assigned by the creator its unlikely to appear when the artwork is solely created for web. It’s also unsafe advice to suggest that the Overprint Preview will visually reveal errors as the amount of Overprint can be very small if assigned to a stroke rather than a fill.
Attempting to use overprint in an RGB document will return an error message to say “…overprinting only affects spot colors.” However it is possible to proceed with the overprint and the error message only displays once. Illustrator also honours overprint when a CMYK document is converted to RGB. With overprint selected within an RGB file you’ll also get an error message when exporting to PSD “some containers in the AI document have been flattened.” It’s possible to turn these error messages off via the Don’t show again option, something I personally resist. It’s also worth noting that the export to PS option will only export layers as used in illustrator, if your artwork is all on one layer in illustrator it will remain on one layer in PS.
The reason you might double click on the overprint is because you have multiple selections some of which might be given the overprint attribute and some which might not.
April 2nd, 2008 at 3:15
I’ve recently been driven mad by:
“some containers in the AI document have been flattened.”
The problem after all was two objects with a blending mode set to screen and overlay, then inadvertently grouped and set to a blending mode of overlay. The resulting PSD export was totally flat. I began by process of elimination, eventually getting the majority of my layers to export and finally found this double/triple blend mode group/hierarchy.
Watch out for this one.
T