Nov 08, 2016

It’s frightening how many errors can become very obvious on a printed document, compared to just reviewing it when it’s up on screen. But unfortunately there is no ‘Undo’ button when your printed items get delivered. Proofing your InDesign work before you send it to be printed is an essential and necessary step in minimising the number of errors, both in terms of content and on a technical level.

Before you even look into performing a Preflight, which we’ll take a more in-depth look at, you should check for spelling errors by conducting a spell check – Edit > Spelling > Spell Check or use the keyboard shortcut Ctrl+Alt+I.

OK, so what is Preflight? It sounds like something you might have to do before an aircraft takes off, and it is really very similar, it is a final check when preparing a design document to ‘take off’ from the screen to go to the printing press.

Before you can export your InDesign document to a print-ready format, you need to make sure that everything is going to print in the way that you want it to. The Preflight panel is going to flag up any technical issues that might cause a problem when you want to package your InDesign file, export it, or send it to a printer.

How to perform a ‘Preflight’?

Preflight is an essential part of the InDesign proof process, and is especially important for addressing technical errors, like missing images, missing fonts or overset text.

Let’s see the Preflight panel in action. Here we have an open InDesign document. And at first glance, all looks fine. But then, if I take a look down at the bottom left of the screen, I notice a little red circle, next to some text reading ‘4 errors’. As long as there is a red circle here, this means that there are errors in the document that need to be addressed before you can send the document to print.

If you double-click on the red circle, you will open up the Preflight panel. You can also access the Preflight panel from the top menu, under Window > Output > Preflight.

The Preflight panel is a simple, one-stop solution for addressing technical errors in your InDesign layouts. Taking just 5 minutes to run a Preflight before you prepare your document for sending to a colleague or sending to print will make a huge difference to the final quality of your work.

At the top left of the panel you can see a check box for turning Preflight On and Off. As a rule, you should always have Preflight set to On. This means that InDesign will actively flag up technical errors as you work, and update them to ‘No errors’ as you resolve them.

In the main part of the panel is the Error window. In this window, Preflight lists the errors it’s found, and categorises them into different groups. At the top here, there’s three Links errors, in this example.

If you click on the grey arrow to the left of the text, the error message expands, to reveal it’s a missing link. Clicking the grey arrow again the name of the missing link is revealed. If you double-click the name of the link, InDesign will take you directly to it in your document.

Click to select the name of the link in the Preflight panel, then expand the Info window at the bottom of the panel. InDesign is trying to help you out here, so it tells you what the specific problem is, and how you can resolve it.

It’s telling you to look in the Links panel and use the Relink button to find the missing file. With the missing link highlighted – it will be flagged up with a red question mark if missing – I click on the Relink button, symbolised by a chain link, at the bottom of the top section of the Links panel.

From here, I can track down the missing link, and click Open to relink it.

After resolving all the errors flagged up in the Preflight panel, the Preflight circle turns green and a message comes up at the bottom of the panel reading ‘No errors’. That’s when you know your Preflight is complete, and you’re ready to prepare your document to send to print.

For more information, take a look at New Horizons' InDesign training courses.