1 May 2013
When I got my first job as a junior designer, I was lucky enough to learn from designers and artworkers who had been in the business for years and really knew their stuff. They taught me the practical side of design and artworking that, quite often, is not taught at university. This exercise is to refresh my memory and to share with anyone who is interested. So here are a few tips on how to prepare InDesign files for print:

It is always a good idea to set up the correct margins and bleed (and size) at the beginning of a project. This saves time later on.

Bleed: for most print documents, this will be 3mm, though for larger items like banners or signboards you can use a 15mm bleed. Also, with brochures you don’t need to bleed artwork onto the left side of the front cover or the right side of the back cover, as this is where the spine of the document is.

Margins: This will depend on the design, but all ‘live matter’ (text and images) should be at least 5mm from the edge of the page (the trim) unless they are full bleed images. Printers like to call the area within the margins the ‘safe zone’.

If the document has quite a few pages and will be folded and saddle-stitched, it is worth considering ‘creep’ when deciding on margins. Creep happens when the document is folded shut and the centre pages are pushed further out (by as much as a few millimetres if the paper is thick). Then the finisher at the printing house will trim the brochure to size, potentially leaving the artwork on the centre pages with a very narrow margin, or none at all. This can be overcome by setting the margins to at least 12mm on documents of this kind.

Here are a few other things to bear in mind when designing for print:

Point size: body copy should be around 9-10pt and small print anywhere from 4.5 to 7.5pt. This is only a very rough guide though, as it will depend on the font used, as each font has a different x-height.

• Fine or small text (smaller than 9 or 10pt) should only be set as a single colour (I.e, black, cyan, magenta or a single spot colour). This will prevent the blurred effect that happens when two or more printing plates have to line up on areas of fine detail.

• The same thing applies to line weight. Anything below 0.5pt should be a single colour. Try to keep line weights above 0.25pt even for single colours.

• Similarly, when knocking white text out of a dark background, a bold font should be used, to allow for dot gain when the ink sinks into the paper. If uncoated paper is to be used, it is best not to use small white-out text at all.

• All Illustrator files imported/placed into InDesign must be set to CMYK.

• They must be either EPS or AI files (not PDFs).

• It is a good idea to create the artwork as close to actual size as possible. When placed in InDesign, the illustrations actual size can be viewed at the top of the screen as a percentage when the picture box is selected.

Percentage screengrab

As you know, vectors can be increased in size without any loss of resolution, but if they are decreased in size then the line weight may become too fine to print.

• If you have created a vector illustration with black strokes or text over a coloured background, it is worth checking that the black is set to print over the top of the colour. You can do this by going to ‘Window’ > ‘Attributes’ then selecting the black object and checking the ‘overprint stroke’ or ‘overprint fill’ box, depending on the shape/line. If this box isn’t checked, then the colour will print up to the black line, but not behind it, potentially creating white gaps around the black shape. This risk has decreased in recent years, as the registration on printers improves.

Attributes screengrab

NB: Never set a white shape to overprint, as it will vanish completely!

• All photographs and Photoshop artwork (i.e, collages or scanned drawings) must be set to 300dpi. When converting images from 72dpi to high resolution, use the ‘Image’ > ‘Image size’ dialogue box, but make sure the ‘Resample image’ box is unchecked. This is because low res images such as digital photos are often around a meter wide. Converting them reduces the size and makes them high res. Resampling them, however, keeps them a meter wide and guesses where the extra pixels will go, making the image appear pixelated.

• Colour images must be set to CMYK and black and white images to grayscale. This helps to prevent black and white photographs from getting weird tints or patterns appearing (known as ‘moiré’) when they print.

• When packaging artwork to send to a printer it is always a good idea to create copies of your image files in a more compact format. So if you have, for instance, a PSD with 20 layers, it is best to flatten it and save as a TIF or Jpeg (but remember to keep the PSD safe, as you may need it in future!).

• Similarly, if you have thumbnail images in a brochure, you can check what size they are by selecting the picture box in InDesign and looking at the top of the screen.

Percentage screengrab

If the percentage is something like 20% then it may be worth editing the image in Photoshop and reducing it to 20% using ‘Image size’ (this time with the ‘Resample image’ box checked). The reason being, there is no use having a little thumbnail in InDesign with a source file that is 30cm wide.

• Of course another problem you may encounter with image files is that they are too small. If this is the case you should try and obtain a larger version of the image. If this isn’t possible then you could change the design or use a different image. Generally speaking, increasing an image to 120% should still be okay. 200% would be pushing it. You could try resampling the image to 300dpi, creating a high res PDF and printing it out on the office printer to see if it has pixelated. Depending on the image, you might just get away with it.

Depending on the print run and budget, your project will either be printed digitally or on a litho press. Most short run jobs will be printed on a digital press, which is cheaper and easier to set up than a litho press.

Every once in while a job comes along that requires something a bit special. If the print run is over 800 or 1,000 it is more economical to go litho. With a litho press comes the option of using spots/Pantones (some of these come in fluorescent and metallic swatches).

If sending a file to print, is it important to remove the Pantones that you are not using from your files (in the case of a digital/CMYK job, all Pantones must be removed). The best way to do this is as follows:

• In your InDesign document, click on the menu at the top right of the ‘Swatches’ panel, and select ‘Add Unnamed Colours’.

Pantone screengrab

• Next, select the Pantone you want to delete and convert it to CMYK with the top right menu, as shown below:

Pantone screengrab 2

• Once the colour is broken down into CMYK, use the same menu to add it to your swatch list. Now click on the original Pantone in the swatch list and click the dustbin in the lower right corner of the panel. A dialogue box will appear, asking if you want to replace the swatch. Select the CMYK breakdown, as shown. This will remove all instances of the Pantone in the document and replace them with the CMYK.

Pantone screengrab 3

• Sometimes when you try to delete the Pantone with the dustbin icon it won’t work (the dustbin icon is greyed out). This is because the Pantone is not only in your InDesign document – it is also in one of your linked Illustrator files. The best way to remove the Pantone is to open the illustrator files, create a shape and fill it with the Pantone then use the ‘Select’ > ‘Same…’ > ‘Fill colour/stroke colour’ menus to find the rogue spot colours and replace them with CMYK.

• Always perform a spell check on a completed InDesign document by going to ‘Edit’ > ‘Spelling’ > ‘Check spelling’. You can also turn on dynamic spelling from this menu.
• You can also go to ‘Type’ > ‘Show hidden characters’ in order to spot any rogue double spaces. Another way to catch these is to use the ‘Edit’ > ‘Find/change…’ feature.

Hope this is helpful ☺ Happy artworking!