How to Prepare and Preflight Ads

Garbage Out, Garbage In

Obvious as it sounds, the most effective thing you can do to ensure that the ads you receive will work in your publication is to give your advertisers the right specifications in the first place. Every publication, no matter how small, should have a media kit, even if it’s a one-page ad-rate PDF, that clearly identifies all of your requirements for the following categories:

» Trim Size It’s unlikely that an ad was designed specifically for your publication. Advertisers frequently repurpose ads, so it’s common to receive ads that are built with the wrong trim size. Your spec sheet should clearly identify the size (and orientation!) for every size ad you offer. If ads that bleed are an option, you should list sizes both with and without the bleeds. The same goes for covers vs. interior page ads; some magazines require a clear space for the glue strip on the side nearest the spine, so an ad on the inside cover may be a slightly different size than one for the back cover.

If you’re the one creating the ads, the best practice is to set the page size to match the trim size of the ad, rather than building an ad on a larger page and drawing crop marks. InDesign CS5 and above allow multiple page sizes in one file, so there’s no reason to use a larger page. If you type the dimensions in the Page size field, and let InDesign create the crop marks when exporting the PDF, both the ad size and the crop marks will always be accurate, and the production artist has the option to include the crops or not when placing your PDF.

» Color space Typically RGB or hexadecimal for digital use, and CMYK for print (but not always; see can we link to an article on all- RGB workflow?). One of the most common errors I see is the use of PMS colors in art and logos. Converting from RGB to CMYK for print usually doesn’t require going back to the client for approval, but convertina  Pantone color to CMYK or RGB can yield very different results. The same holds for converting anything to grayscale. Rather than run the risk of an unhappy customer, I always ask them to resubmit the ad using process colors, unless they specifically give the OK for me to convert them.

» Resolution People seem to have a really hard time understanding the concept that for print, you need 300 dpi at the final size, and that if you take a 300 dpi image and scale it up 200%, it is now only 150 dpi. I see ads all the time with 72-dpi logos or photos copied from the Web. Just because it looks OK on screen, that doesn’t mean it will look good in print. It’s the unenviable task of the desiger/production artist to explain to the advertiser that if they don’t redo the ad with a high-resolution image, it will loook blurry and jaggy.

» Ink coverage For print documents, you’ll want to ask your printer what the maximum ink coverage is for their press, and add this to your spec sheet. And, don’t be surprised if the ad designer has never heard of this one!

Ad Portals

Ad portals take the burden of preflighting off the production artist and give it back to the designer. The advertiser uploads their ad file to the portal, and receives instant feedback about whether the ad passes preflight. If the ad contains the wrong color space, trim size, resolution, etc., it is rejected and the advertiser knows right away that they need to fix it. Best of all, the production department never even sees the failed ads; they only receive files that have made it through the portal.

Due to the cost of setting one up and maintaining it, ad portals are typically used by larger publishers who have several magazines in production on an ongoing basis.

Now, if only parents could set up “dating portals” for their kids . . .

How to see what’s wrong, and fix it.

Sadly, no matter how detailed your spec sheet is, a lot of advertisers will totally ignore it, so you will still have a lot of ads that are not print quality.

Use a dummy

There are several ways to preflight files with InDesign; but for ads, I find it best to use a multi-step approach. The first step is to use either InDesign’s built-in preflight panel, or a third-party app such as FlightCheck from Markzware, just to see if there are any problems. InDesign’s built-in preflight panel, will show you everything about the entire publication, but that’s a lot of information to wade through if you just want to see the info about one ad. It’s easier to place the ad by itself into a new document, so you only see the errors in the ad itself. Typically, I make a copy of the publication file, delete all of the pages, and insert a new blank page, so that the master page margins & guides match the live document. I use this dummy doc to place ads into while checking them out.

The ad failed; now what?

If everything is hunky dory, and there are no errors flagged, chances are the ad will be fine. But, if the ad fails the preliminary test, all you may know is that your ad has something in it that is low-res or uses a spot color. This could be enough to ask the advertiser to resubmit it; but I find that I get better results if I can tell them exactly what the problem is and how to fix it. Unfortunately, the Preflight panel will tell you that there is a low-res image but not which one it is, or where. The same goes for Markzware’s FlightCheck; it’s fine for verifying that a PDF’s color space & resolution are OK, but not much help in identifying which object caused it to fail.

Figure 4: Acrobat Pro has sophisticated preflight tools with presets for many common types of presses.

Fortunately, Acrobat Pro has sophisticated tools for identifying where the problems lie. So, why not just start there? I probably should, but I keep foolishly thinking that maybe this time, this ad is going to be perfect, and if it works, it’s a lot faster to just place it in InDesign or drop it on the Flightcheck icon and verify that it’s OK.

Figure 5: Acrobat Pro lists each item that contains an error.

In Acrobat Pro, if you select Preflight under the Tools>Print Production, you’ll see a long list of presets to choose from (Figure 4), and if that’s not enough you can customize any of them or make your own. I usually select the Prepress>Magazine Ads preset and click the Analyze button. The other one, “Analyze and fix” will convert spot colors etc., and I’m not ready to do that yet.

When you click Analyze, Acrobat will give you a report that shows more info than you ever want to know about the PDF (Figure 5). When you click on an error flag, you can select either the “show” button to the right of it, or the “show in snap” button below, and Acrobat will show you the object that caused that flag (Figure 6).

Figure 6: The Snap View identifies the problem image.

There are other useful tools in Acrobat Pro for identifying specific problems. If you are going to use Acrobat Pro at all regularly, it’s really worth taking a few minutes to customize your toolbar with the tools you use most often (Figure 7).

Figure 7: Customize your Acrobat Pro toolbar with the tools you use most often.

For instance, if I know that a PDF contains spot colors and it doesn’t have any image resolution issues, I often prefer to just click the Color Separations Preview icon , which brings up a window showing all colors in the document (Figure 8). Turning off the Process colors will show me just those elements that use the spot color.

Previewing color separations in Acrobat Pro

This dialog also contains the “Total Area Coverage” field; if you set the number (320 in my screenshot) to your printer’s maximum, any areas of the PDF that exceed that value will be highlighted.

The Convert Colors icon (just to the right in my customized toolbar) brings up the Convert Colors dialog, which is used to manually convert colors (such as Spot to Process). Again, this is an option of last resort; I always offer the customer the option of resubmitting an ad before converting spot colors, because the converted colors are often strikingly different.

Surprisingly, it’s been my experience that ads coming from professional ad agencies have as many, if not more, problems than those from in-house designers. But, if you follow these guidelines, the ads in your publication, or those you send out, will look good in print, and also keep your production department happy.