There’s more to designing for print than simply coming up with eye-catching copy and images – there are technical issues which can make the difference between a smooth process and a printing disaster. Our experts take you through some of the technical essentials from Trim Size to TAC.
The trim size of the magazine is the final size the magazine will be once it has been printed.
If you are designing an advert with a professional design software package such as InDesign which natively handles page bleed, you will set up your document to the appropriate trim size. If you are using software that does not natively handle bleed, then you will need to set your document up to the bleed size, and add the bleed measurements to the type/safety area measurements.
This is the area of artwork outside of the trim area, and is needed to counter the movement on press during printing and binding. Typically, this will be 3mm in the UK and Europe and 0.125 inches in the USA.
Any design element you want to go to right to the edge of the page, such as a background colour or an image, must extend to fill the bleed area.
This is the area that is safe for the main content of your pages, such as text, logos and images. Content shouldn’t be positioned right to the edge of a page, due to movement on press and binding, as it could be cut off. Additionally, where a publication is perfect bound, text on the inner edge may need to be further from the trim edge, in order to ensure it is not lost in the curve of the spine.
With double-page spreads, you will have a type/safety area on each page, so there is an area in the middle, called the gutter, where content should not be placed.
You should avoid running text including headlines across the spread. Images can run across a spread, but you should avoid positioning them so sensitive parts of the image fall in the gutter.
If it is important to you that a headline or significant part of an image runs across a spread, please discuss this with your publisher! They can work with the printers to get bespoke recommendations on how far content should be ‘pulled out’ to allow for the gutter. Such advice is only a recommendation – there can never be absolute guarantees that the result will look as expected, as the movement on the press can’t be predicted.
Elements such as borders should be within the type/safety area.
The recommended resolution for print is 300dpi, that is 300 dots per inch of image. Be aware that it is the effective resolution on the final PDF which is important, not the resolution of the starting image.
For example, if you had an image with a resolution of 72dpi, and used it at 24% of the original size, the final output resolution would be 300dpi. If you have an image which is 300dpi, and you used it at 200% of the original size the final output resolution would be 150dpi.
The InDesign Pre-flight helper can be set up to warn you of low-resolution images as you design.
Magazines are printed using the ink colours described as CMYK – Cyan, Magenta, Yellow and Black. Therefore, you should design your advert using the CMYK colour space, and choose your colours accordingly.
Avoid using the RGB (Red, Green Blue) colour space or spot colours, or convert them to CMYK when you export for press.
Be particularly careful when choosing a black, particularly for black text. Text which is 12pt or smaller should be black only – Cyan: 0, Magenta: 0, Yellow: 0, Black: 100.
A ‘rich’ black is when you add some cyan, magenta and/or yellow to your black to ensure that it appears as a deep black when printed. This should be used only on large areas of black. Publihing companies often have a set ‘rich black’ that they often use, but otherwise a combination such as Cyan: 30, Magenta: 30, Yellow: 30, Black: 100 should work well.
Be aware that if you have fine/small white text on a rich black background, particularly when using high levels on Cyan, Magenta and Yellow, there can be a risk that some ink may spread into the text area.
Ink Limits and Total Area Coverage (TAC)
In print four inks are used – Cyan, Magenta, Yellow and Black. If your design combines 100% of all four colours, this would give an ink coverage of 400%.
Generally, in magazine print the limit is 300%, though on some papers like newsprint it could be less, typically 240%. So, no element of the page, including images, should exceed the TAC limit.
If the ink coverage is too high, the paper will be unable to properly absorb the ink, which could lead to ink running, or rubbing off onto another page, pages sticking together and a host of other problems.
To ensure your files don’t exceed the maximum ink coverage, or to fix ink coverage issues:
- Text and vector objects – select the elements which are high and adjust the ink levels so they add up to less than the maximum ink levels.
- Images – in Photoshop convert the image to a suitable CMYK profile with a 300% ink limit.
Your publisher should be able to recommend colour profiles to use – otherwise, if the ink limit is 300%, we would recommend:
- U.S. Web Coated (SWOP) v2 – for printing in the USA
- ISO Coated v2 300% (ECI) – for printing in the UK and Europe
There are various ways to check ink levels:
- Pit Stop Pro – Specialist PDF pre-flight software can be set up to warn of ink levels on a PDF.
- Acrobat Pro – In the Print Production Tools, select Output Preview. Tick the Total Area Coverage and select the limit you want check for. It will highlight elements which are over in the selected colour. Also hovering over sections of the file will show the ink levels in that area.
- InDesign – Open the Separations Preview box, change view to Ink Limit, and set the required limit to check for.
- Photoshop – Open the Info panel, and under panel options change the Second Colour Readout Mode to Total Ink. This will then show the ink levels for the area underneath the curser, so you can check as you move the cursor around.
Some of these applications will only check vector objects, and don’t check ink levels of the images or take overprints into consideration.
Be aware that transparent elements, such as drop shadows, or gradients used to darken parts of images, can push the ink levels higher than an element checked for ink levels on its own. To deal with this issue, you may need to limit ink levels in images to a level below the maximum ink levels allowed. Alternatively, compile all the transparent elements along with your image into a single flattened image, and then limit the ink levels on that.