Sep 25 2008
In one of the InDesign forums, a subscriber asked how he could “fatten up” his artwork in InDesign, because the InDesign file was going to be used as artwork for embossing. To ensure that nothing would be undercut or too delicate in the embossing plate, he was asked by his printer to spread all artwork — text, an Illustrator logo, and a bitmap signature. He needed to perform a trapping operation called “spreading.” Here’s my answer to him:
While InDesign can’t create trapped content, there is a way to create a trapped PDF from InDesign. For the job described, which requires “fattening up” all artwork, you must convince InDesign that it needs to spread the artwork. It looks long-winded when you see all the steps below, but it’s not really that bad. For this to happen, you need three things:
-artwork that’s lighter than the background (I’ll use C100 in this example). And your signature must be a bitmap TIFF. (OK, so maybe you actually need four things.)
-a custom trap preset in InDesign
-Distiller (if you don’t have Distiller, you can’t do this)
- Turn your Illustrator artwork to 100 cyan, then update it in InDesign. Yes, I know it will emboss — not print in cyan — but it doesn’t matter what color it appears to be: they’ll output that plate and use it as the basis for an embossing die.
- In InDesign, color your scanned signature 100 cyan: You can just drag the 100 cyan swatch on top of the signature frame without selecting the frame first. Alternatively, select the sig artwork with the white arrow, and choose the cyan swatch.
- Change all your text to 100% cyan.
- Create a big 100% black object behind everything. This creates a situation InDesign is willing to trap.
In InDesign, create a trap preset that spreads the art by whatever amount the printer suggested: let’s say .004″. (Max is .111″)
- Go to Window>Output>Trap Presets
- From the Trap panel menu, choose New Preset.
- Set the Trap Width default to .004″, as well as the Black trap width (make sure it’s INCHES, not points or picas)
- Under “Images,” everything but “trap images internally” should be checked. Click OK.
- Reopen the Trap Presets panel menu, and choose Assign Trap Preset. Choose your new trap preset from the list, select the range of pages to which it should be applied, and click the Assign button. And click Done. (It’s stupid to have to reopen the panel to accomplish this, but you have to do it. Just play along.)
NOTE: this does not actually trap your file. It creates trapping rules that ordinarily are exercised by a RIP that performs the traps. That’s what happens in the next steps: InDesign sets up the trapping parameters, and Distiller acts like a RIP. Here we go:
- In InDesign, File>Print.
Printer: PostScript File
PPD: AdobePDF 7, 8 or 9 (whatever you have)
Under “Output,” choose:
Color: In-RIP Separations
Trapping: Application Built-In
- Click Save, and InDesign creates a PostScript file
- Launch Distiller, and choose the PDF/X-1a:2001 setting
- Distill the file and look at the resulting PDF: all your cyan artwork will be .004″ fatter. The trap “rim” itself is set to overprint, but none of that matters: when the printer outputs the cyan plate, they now have their beefed up artwork for the embossing.
NOTE: I’ve exaggerated the spread amount to make it obvious in the illustration below.