A tips reader wrote us this week: “I have an issue with drop shadows and spot colors in Adobe InDesign. When I use a drop shadow in front of a spot color background it looks fine in InDesign, and prints properly as spot color separations. But a white box shows up around the image in Acrobat when I make a PDF to show the client. Is there a way around this problem?”

An excellent question, and one that comes up a lot for designers working with spot color. There are several ways to make sure your spot color jobs preview properly in Adobe Acrobat.

We’ll cover 3 different techniques in this tip. Plus we’ll throw in an extra tip on how to avoid that annoying white box when printing on cheap inkjet printers.

Overprint Solution #1: Acrobat’s “Overprint Preview” option.

The first and simplest solution is to turn on the “Overprint Preview” option in Adobe Acrobat. This is a tremendously useful feature for soft-proofing PDFs before printing. Oddly, Adobe has hidden this valuable option in increasingly hard to find menus over the years. Here’s where you can find the Overprint Preview command in various versions of Adobe Acrobat:

Acrobat 5: View > Overprint Preview

Acrobat 6-7: Advanced > Overprint Preview

Acrobat 8: Advanced > Print Production > Overprint Preview

This feature provides designers an indication how overprints will look on the finished printed project. The downside to this solution however is that your clients must be viewing at your PDFs in the full version of Acrobat, plus you’ll need to train them to turn on the overprint preview option.

Overprint Solution #2: Export your PDFs with Acrobat 5.0 or later compatibility.

The second solution is to make a minor change to how you export your PDF from Adobe InDesign. By selecting Acrobat 5 (PDF 1.4) compatibility, your resulting PDFs will include additional transparency information that helps them preview more cleanly in Acrobat.

This simple adjustment to how you create PDFs may be enough to solve the problem with your clients previewing spot color overprints. This does require that your clients are using Acrobat 5 or later. Since Acrobat 5 was released seven years ago in 2001, the chances are good your clients should be able to open these PDFs.

However, your print shop may feel differently. The older Acrobat 4 format flattens all transparency effects, which many print service vendors still prefer. Many print vendors provide their own PDF presets that do not allow transparency in the saved PDF. Check with your print shop about their preferences.

Overprint Solution #3: Convert Spot Colors to Process for Proofing.

Here’s the last option we’ll cover today for providing a PDF your clients can proof that’s free of the annoying the white box problem. That’s to convert all spot colors to process when generating your PDF proof.

When exporting your PDF from InDesign (File > Export), choose the Output options in the Export Adobe PDF dialog box, and click on the “Ink Manager” button in the color section of that window.

In the Ink Manager window, turn on the “All Spots to Process” checkbox.

This will create a process-color version of your PDF that should preview properly under almost all circumstances. However it is important that you remember this PDF will not print spot color properly, and should not be given to the final press for separations.

Bonus Tip: Simulating Overprints on Composite Color Printers.

Finally, if that annoying white box is showing up when you print your PDFs on a typical desktop color printer, there is a hidden option to fix that problem too.

In Acrobat’s print dialog box, click on “Advanced” and look for a “Simulate Overprint” checkbox.

We hope this variety of tips will help vanish those annoying white boxes from overprinted shadows from now on!

Source: This tip is inspired by an email question from reader Sean Bolger at EarthColor. The timing is impeccable, because Jason Hoppe is leading a workshop this Wednesday in Seattle titled Acrobat: Preflighting PDFs for Printing where he’ll be digging into this and related topics much more deeply.

January 16 — Acrobat: Preflighting PDFs for Printing. Adobe PDF files are ideal for today’s prepress workflow — but they have to be created properly. In this 90-minute session learn the details on how to make sure your PDFs will print flawlessly when they arrive at the print shop.