.PSD file in Illustrator won't let me set it to overprint?

[shorty83]

Hi, I have another question for all you experts...I have two .PSD files, one is a spot green color and one is black. They both have transparent backgrounds. I have to bring them both into Illustrator and make them both overprint. The one with the green in it will let me set it to overprint, but the one with the black in it will not! Anyone have a clue how I can make it so it will let me click overprint?? I have to do it this way because I have no trapping software and have to do it in application

Thanks!
M

 

[pcmodem]

Re: .PSD file in Illustrator won't let me set it to overprint?

Try setting the Transparency to Multiply.

 

[phantasm]

Re: .PSD file in Illustrator won't let me set it to overprint?

Hi M,

Ai has quite a few rules when it comes to overprinting and images - especially those with transparencies.

Few main points: it can depend a little on what version of Ai (from memory). Ai CS3 is the most flexible. But it also depends on whether you are link/placing or embedding the image.

I have attached an example of what's possible when you embed the images. I created two transparent image types in PS; the left ones are CMYK, with only the Black channel having any "color". The right ones are CMYK + Spot images created in PS - there is no CMYK content, just information on the spot orange channel. I then embedded the images on a radial gradient background in an Ai document (*View -> Overprint Preview* enabled). By default (the upper row), overprint is not set which mainly shows with the spot image, although the slightly dirty halo around the top left black blob can be noticed.

I then copied both embedded images (lower row) and ticked overprint on both. I think this is what you are looking for.

However, it is not possible to set overprint if the image has been linked - ie. is not embedded. With linked images, Ai's default behaviour appears to be to +not+ overprint CMYK images, but to set overprint if the image contains a spot channel.

I'm sure you know this, but to embed an image in Ai, simply untick the *Link* option in the *Place* dialogue window or use the *Embed* button in the top context-sensitive toolbar only found in Ai CS3.

I hope this is of help,

Nick

 

[John W]

Re: .PSD file in Illustrator won't let me set it to overprint?

If using application trapping, a good ROT is to do the work as early in the process as possible. This is contra to today's thinking of doing nothing until the last step.

You can handle this situation from Photoshop in two ways; utilize the cmyk channels and trap by the amount you need based on size as use in Illy. Then recolor as required, resplit the files. Or you can trap within multiple layers (including soft traps).
OR
You can always place the cmyk under the spot color in Illy and set the spot color above to do what you want, darken, multiply, overprint, whatever. At the very worst, you can employ the two page solution, rip one color from page one and the other from page two (this technique is only used for worst possible scenarios).

Always keep in mind that this was possible in postscript workflows from the very beginning so there is virtually nothing that cannot be handled at app level - we do it all day long including cmyk, spot colors, metallics, opaques, varnishes, embossings, etc.

John W

 

[shorty83]

Re: .PSD file in Illustrator won't let me set it to overprint?

Well, I embedded the image and it worked like a charm! So simple! Thanks for all your help everyone!!

M

 

[phantasm]

Re: .PSD file in Illustrator won't let me set it to overprint?

> {quote:title=prepression wrote:}{quote}
> There are a number of problems I see here. First is using PSD files in place of proper EPS files. PSD is a working file format and should only be used as such. Secondly, I assume your Photoshop file was saved with a transparent layer. Another No-No. RIPs typically don't like PS files saved in this manner. Why not retrace the image in illustrator using live trace (or redraw it) and then apply a transparency and overprint to it? I think that would be a better solution in the future.
>
> Try this resource for more info:
>
> http://www.amazon.com/Exploring-Digital-PrePress-Delmar/dp/141801236X

Hi Harry,

I can't remember the last time I had to use EPS or come in contact with it (although I originate artwork much more than receive it). I personally use a variety of local and national UK printers for spot, CMYK and custom Hi-Fi print work (mostly based on Ai artwork), much of it with embedded PhotoShop files. Never had any artwork rejected or requests for re-work. I'm not aware of the printers having to modify my work to make it suitable either.

It all depends on your methods and experiences. When working in Ai, I personally find linked EPS files (in fact, linked files of all types) too restrictive - both creatively and for controlling technicalities such as overprint.

And don't get me started on the bad karma the mention of DCS EPS files brings me LOL! Since the release of Ai CS3, I personally consider DCS EPS files to be dead and buried.

Best wishes,

Nick

PS - what do you mean by "working format"? To me, an editable format allows for maximum flexibility and control. I just can't quickly go and edit an EPS in the same was as a native/embedded/bitmap/PhotoShop file just because the sales department got the phone number wrong again ;-)

 

[shorty83]

Re: .PSD file in Illustrator won't let me set it to overprint?

> {quote:title=prepression wrote:}{quote}
> There are a number of problems I see here. First is using PSD files in place of proper EPS files. PSD is a working file format and should only be used as such. Secondly, I assume your Photoshop file was saved with a transparent layer. Another No-No. RIPs typically don't like PS files saved in this manner. Why not retrace the image in illustrator using live trace (or redraw it) and then apply a transparency and overprint to it? I think that would be a better solution in the future.
>
> Try this resource for more info:
>
> http://www.amazon.com/Exploring-Digital-PrePress-Delmar/dp/141801236X

Well, I thought about this and sent it to the RIP and all is well, everything separates and traps wonderfully. To redraw this logo in Illustrator would be nearly impossible to get the right look. The way I look at it is, I am very limited on what I can do with files since I have to do all trapping manually in application, so if I get something to work I don't really care what format it's in!

 

[John W]

Re: .PSD file in Illustrator won't let me set it to overprint?

It all depends on your methods and experiences. When working in Ai, I personally find linked EPS files (in fact, linked files of all types) too restrictive - both creatively and for controlling technicalities such as overprint.

When files with embedded images require imposition from within ai, often one can end up with humongous files, indeed files that will not RIP or manage because of file sizes (>1GB). Linked files OTOH, do not cause such bloating and are therefore desireable at times. Embedded files are also often to produce poorer quality because they are embeeded at size as where linked files may be sized down. For the smooth lines on the side of a car as an example, a placed image at 50% produces superior results (less stepping) than does an embedded version or even a pdf version FTM (downsampling!). If editing of an embedded image is to occur, the extraction process also loses any of the aforementioned sizing quality gains. So only embed when forced to must be the rule, IMO.

John W

 

[phantasm]

Re: .PSD file in Illustrator won't let me set it to overprint?

> {quote:title=John W wrote:}{quote}
> When files with embedded images require imposition from within ai, often one can end up with humongous files, indeed files that will not RIP or manage because of file sizes (>1GB). Linked files OTOH, do not cause such bloating and are therefore desireable at times. Embedded files are also often to produce poorer quality because they are embeeded at size as where linked files may be sized down. For the smooth lines on the side of a car as an example, a placed image at 50% produces superior results (less stepping) than does an embedded version or even a pdf version FTM (downsampling!). If editing of an embedded image is to occur, the extraction process also loses any of the aforementioned sizing quality gains. So only embed when forced to must be the rule, IMO.
>
> John W

Hi John,

I agree with you that at extreme file sizes, working with embedded artwork can be too traumatic when it comes to saving - especially when the files are PDF compatible (default). I tend to top out at 250Mb file sizes, but with newer and faster hardware appearing all the time, this limit will rise.

However, I do not understand the comment about reduced quality. When embedding an image, you can naturally change the resolution by scaling. The effective DPI of the image is stated in Ai CS3's top context-sensitive toolbar. So if you scale the image to be 300dpi or more (if the image had a dpi setting, this will be used as its default), it would output the same as a linked image also set to 300dpi.

You have to take care at output stage that no downsampling takes place, if that's not what you wish. But otherwise have you got any experience of this being contrary?

Finally, I know I'm now going to be both annoyingly biased and smug, but I have no problem with editing embedded images without loss... ( [Phantasm CS Studio plugin link|http://www.phantasmcs.com/features/index.html#editimage] ).

All the best,

Nick

 

[John W]

Re: .PSD file in Illustrator won't let me set it to overprint?

However, I do not understand the comment about reduced quality. When embedding an image, you can naturally change the resolution by scaling. The effective DPI of the image is stated in Ai CS3's top context-sensitive toolbar. So if you scale the image to be 300dpi or more (if the image had a dpi setting, this will be used as its default), it would output the same as a linked image also set to 300dpi.

You have to take care at output stage that no downsampling takes place, if that's not what you wish. But otherwise have you got any experience of this being contrary?

If a 300dpi image is placed at 50% it has an effective resolution of 600dpi. Any process that downsamples to say 300dpi will cause a loss of edge quality, period.

Since creators often embed their images, they often disregard this feature and 'optimize' to 300dpi, which would be wrong. Further to that if the creators make the pdf, they may/will use a job option setting that also negates the extra resolution. Because these things are often not in prepress's control, we have little say in the matter. Okay, if you are in direct contact with the creator, the education can occur but often as you know this is not the case at all.
Of course setting the image to 300dpi is bad (either during embedding or on the original), when an effective 600dpi is available, (car brochure prev mentioned).

From vast experience, I can say that keeping the version of Illustrator that was used originally is always least risky and of course older versions do not offer the same features as newer ones. So embedding IMHO is a no-no. As an alternative I would be somewhat comfortable with an embedded image as long as the native image is also provided.

John W

Edited by: John Willis on Jul 27, 2008 8:38 AM

 

[phantasm]

Re: .PSD file in Illustrator won't let me set it to overprint?

Hi John,

> {quote:title=John W wrote:}{quote}
> If a 300dpi image is placed at 50% it has an effective resolution of 600dpi. Any process that downsamples to say 300dpi will cause a loss of edge quality, period.

Naturally. But what you are otherwise describing is a lack of training with the designer / Ai operator rather than a technical limit. Embedded images can be set to, and output at 600dpi or any resolution you wish. The latest brochure work I've done was at 450dpi where possible and all images were embedded and output as such. The job went through fine.

Different techniques, but neither is wrong if used correctly.

Best wishes,

Nick