To achieve the best printed results, pages must be designed and made-up with consideration for the complete production process. Here, we set out some guidelines on how to avoid the most common mistakes.
Bleed
Printed matter which runs to the edge of the page must extend beyond the page edge. This is called ‘bleed’. It is recommended to allow at least 3mm bleed outside the trimmed area, to allow for variations within the trimming process.
Margins
Elements which do not bleed should be kept to at least 5mm inside the trimmed area. Anything closer to the edge is in danger of being trimmed off.
Perfect binding
Perfect-bound products do not open flat. Therefore, there will be elements of the page that sit towards the spine area that will not be seen. Headley Brothers recommends that you include a margin in the back of all pages at the design stage of at least 10mm, to ensure that all elements of the printed page will be visible to the reader.
Bulking
Bulking is evident in large saddle-stitched products, since each section is progressively stitched inside the previous section. This forces each subsequent section further away from the spine by the thickness of each section wrapped around it. For every 1mm of book thickness, 1mm will be trimmed off the page width. A 3mm thick A4 magazine will have the centre pages trimmed at 207mm, not 210mm. You should bear this in mind when laying-out your pages.
Elements across spreads
Where design elements go across a spread, the accurate alignment of the image cannot be guaranteed over the two pages. The fold is subject to a variance in any print run. Typically, the variance is +/- 1mm. Subject matter that can be most obviously affected by this variance are tint-edges and rules (especially diagonals) and text.
Fine lines & small lettering
Fine lines and small text should be designed to be reproduced out of one colour only to avoid unachievable registration tolerances.
Colour consistency & paper stocks
If your publication’s cover is to be printed on a different paper stock to the text pages and potentially by a different printing process, bear in mind this could cause difficulties in colour consistency across the inside-front or back cover to the first or last page of text. Try to avoid a design running across the inside covers to the text.