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In a world where com­pos­ite PDF is the norm, this DCS work­flow no longer fits. With simple CMYK work from Pho­toshop, pla­cing ele­ments and gen­er­at­ing sep­ar­a­tions is simple. The graphic is still held as sep­ar­ate plates, but presents to the user as a com­pos­ite image.

The prob­lem arises, how­ever, when attempt­ing to take a CMYK+spot(s) file from Pho­toshop and attempt place into any applic­a­tion — includ­ing InDes­ign 2.0. Ulti­mately, it would be great to be able to place a single file that con­tains bit­map and vec­tor inform­a­tion, as well as hold­ing trans­par­ency and spot col­ours. Presently, the only file format that sup­ports this fully is DCS. Whilst you can cre­ate Illus­trator 10 .ai or .pdf files con­tain­ing CMYK bit­map and spot col­our vec­tor objects, Pho­toshop is still largely the tool of choice for cre­ation of spe­cial effects.

Pho­toshop allows spot col­our chan­nels to be cre­ated, but the only sup­por­ted out­put formats are EPS, DCS and Pho­toshop PDF. In all of these formats, any trans­par­ency is not retained.

There­fore, this tech­nique (which has been used in pro­duc­tion) may assist you in com­bin­ing the power of Pho­toshop and extend­ing its spot chan­nel sup­port, and the power of trans­par­ency in InDes­ign to assist us in cre­at­ing a print­able job.

The pro­cess:

The over­view is: cre­ate two Pho­toshop PDF files, place them on top of each other in InDes­ign 2.0. The bottom-most file is a CMYK only Pho­toshop PDF, and the topper-most file is a Spot-only Pho­toshop PDF. This tech­nique relies on the Trans­par­ency Flattener in InDes­ign 2.0 to weave its magic to gen­er­ate a com­pos­ite output.

Step 1: cre­ate the source graphic ele­ment in Pho­toshop. In this example, we have a masthead that con­tains a Bevel&Emboss Pho­toshop layer style. Our goal is to make the col­our of the masthead a spe­cial col­our. (in the real­world example, this was prin­ted as a metal­lic sil­ver colour). Don’t cre­ate the spot chan­nel yet. Save it as a Pho­toshop PDF (retain­ing trans­par­ency, vec­tor inform­a­tion and res­ult­ing in a com­pact file).

In this file, the text has a white (or knock­out) col­our. Its goal in life is to act like a “cookie cut­ter” and remove the ink from under­ly­ing ele­ments at print time. The Bevel&Emboss effect is cre­ated using a Black ink, so it will still appear on the black plate at print time.

Step 2: Take the same Pho­toshop PDF file:

• Turn off any effects.
• Change the white/knockout col­our to Black. Choose a % of black that equals the % of spot col­our ink you would like. In this example, as the ele­ment is a vec­tor text ele­ment, it is just filled with 100% Black.
• double check and ensure where you have black, you want the spot ink to appear
• Mode>Convert>Grayscale. The will con­vert the black ele­ments to 100% Black.
• Mode>Convert>Duotone. This will then per­mit you to change the Black to a named spot chan­nel. Thank­fully in Pho­toshop 6 or 7, this will be clipped inside the vec­tor text element.
• For Advanced Users: you can also use other Layer Styles in Pho­toshop to ‘feather off’ the spot ink to cre­ate a high­light effect.

Do not make any pos­i­tion changes to the file. Set the chan­nel in the Duo­tone to the same spot ink you are going to use in InDes­ign. This can be “Ink Aliased” at out­put time.

Step 3: As you will notice, sav­ing as an EPS or PDF — trans­par­ency is not retained in this pro­cess. Don’t panic, we’re going to fix this in InDesign.

So we have two files: one being the Com­pos­ite CMYK object saved as a Pho­toshop PDF, and another saved as a Pho­toshop PDF con­tain­ing a Spot col­our. In both files, there is vec­tor data ensur­ing high qual­ity out­put. In this example, I am using the .PDP file exten­sion: the data inside the Pho­toshop PDF file is exactly the same; all I have done is adjust the exten­sion. This will enable InDes­ign to Edit Ori­ginal into Pho­toshop automatically.

Step 4: Go to InDes­ign 2.0. Place the file saved in step 1.

Step 5: Place the file saved in step 3, pos­i­tion­ing it exactly over the top of the file placed in step 4. Use the trans­form palette to get 100% place­ment accur­acy. Don’t worry about the “white“ (knock­out) col­our from the placed file.

Step 6: set the top object to 100% Mul­tiply using Window>Transparency. Almost magic­ally, the white col­our is removed, yet the spot col­our remains. Leav­ing this at 100% Mul­tiply, at out­put time the spot col­our is retained (not con­ver­ted to process)

To make the print­ing pro­cess a little more dif­fi­cult, here the layer which the two ele­ments are placed onto have been moved behind the image.

Step 7: Export as PDF, or Print to the Acrobat Dis­til­ler. In this example, I prin­ted using Com­pos­ite CMYK. Its a little dif­fi­cult to fathom; but spot col­ours are held in this pro­cess (unless you use InDes­ign 2.0’s Ink Man­ager to con­vert them back to pro­cess at print time)

In the above screen dump, I am using Quite Reveal­ing to show the back­ground col­our from the Com­pos­ite PDF. As you can see, the first placed CMYK PDF ‘cuts out’ the col­our in the back­ground: in this instance, the PANTONE 264C Spot Colour.

This above screen dump shows the PANTONE 340 C as cre­ated in the second Pho­toshop file

Here is the black plate. The Bevel&Emboss added in the first Pho­toshop PDF is retained, and over­prints the spot col­our correctly.

How does this work?

The first file you place (CMYK) ele­ment acts like a ‘knock­out’ ele­ment, remov­ing any items under­neath. The second file placed (EPS Spot) then over­prints the under­ly­ing CMYK object. As InDesign’s flattener is smart, it does not knock­out under­ly­ing ele­ments. It also does not change their col­our in the flat­ten­ing as the top object is a spot col­our. Other blend modes such as Lighten or Darken do attempt to change the col­ours — so the final doc­u­ment may be forced into CMYK.

What’s the Benefit?

What does this provide that DCS does not? The abil­ity to gen­er­ate a com­pos­ite PDF. As soon as you place a DCS file into QuarkX­press, InDes­ign or Page­Maker — you are for­cing the out­put to be sep­ar­a­tions. In mod­ern Post­script 3 or Extreme work­flows, recom­bin­ing presep­ar­ated out­put is dif­fi­cult, and not the default workflow.

If you are in Aus­tralia, you may have seen the June 2002 issue of the Fox­tel magazine. It used this tech­nique. Sup­plied as a com­pos­ite PDF with Spot col­our, it cor­rectly sep­ar­ated, was trapped and prin­ted as a metal­lic. The Bevel&Emboss in the K plate over­prin­ted the silver-metallic spe­cial col­our. This plate is still a vec­tor element.

Thanks to: Matt Phil­lips, Ben Hewitt (who tested this out on a live job!) and Alan Rosen­feld (for listen­ing to my rant­ing about this in Bris­bane). A big thankyou to Aaron Cliff from Fox­tel magazine for send­ing a bet­ter qual­ity image — and more import­antly, being brave enough to pion­eer this technique.