Despite this magnificent feature being introduced since the first release of Creative Suite, I am still amazed at the amount of people who either don’t use this preview, or know it exists.

For those who don’t know what i’m talking about, Separations preview is a way of viewing the InDesign file so that it more closely resembles what it will look like once printed. It also lets users toggle through the ink separations which are available in the document.

Using separations preview it is possible to determine common prepress errors such as:

• Unwanted overprints, such as white overprints suddenly disappearing from view;
• Items set as either non-printing objects or non-printing layers (they will disappear completely from view);
• Undesired black overprints, such as a solid black overprinting a photograph and still having the photograph visible instead of knocking out;
• With the exception of photographs – real blacks instead of faux blacks (e.g. items meant to be 100% black only but instead composed of all four process colours);
• Effects which won’t work with spot colours such as color burn, soft light or overlay (the areas over spot colours using these effects will dissappear);
• The use of Registration colour (will appear on every single separation as a solid);
• Any spot colours which shouldn’t be in the document – either because they aren’t actually in the design but are still in the swatches palette; or if they were meant to be converted to process using the ink manager;
• Unwanted knockouts, such as a dieforme overlay which wasn’t set to overprint and has knocked out the artwork underneath it.

Similarly, Adobe Acrobat has a separations preview but goes some steps further such as:

• How the artwork will appear based on different colour profiles; or to simulate black ink and paper appearance;
• Can show whether the images in the PDF are CMYK or other colour spaces, such as LAB, RGB etc.

This is only using separations preview as well… haven’t even mentioned the Ink Limit view available in both Acrobat and InDesign; or the Flattener preview available in InDesign… but will save them for another post.