Design Issues:
Page/Code numbers should be kept away from the edge of the page and preferably centred. If printed by web offset, the design must allow for variation in folding as this can result in copy being trimmed off with uneven borders between pages.
If designs or illustrations need to run across a pair of pages, use the pages at the centre of sections.
A 16 page book should have double page spreads on pages 4 & 5, 8 & 9, the centre pages and 12 & 13. this allows checking to be carried out more often and more easily, particularly at the folding stage.
Thickness
As the book becomes thicker the inside pages will be shortened: a rough guide is for every 1mm in book thickness, allow 1mm less on the page width, e.g. an A4 portrait 3mm thick book will have the centre pages at 207mm not 210mm.
A very thick book can result in slight tearing at the ‘V’ of the spine.
The thicker the book the less satisfactory it looks. The wires at the centre of the book can fail to hold the pages in if the book is under a lot of use.
If using a repeat design that bleeds, some variation will show – equally a solid, finishing just short of the paper edge and repeating on all pages, will show variation when the book is ‘flicked through’.
Production Issues:
Grain directions should always be parallel to the spine of the book.
Allow adequate trims for head, tail and foredge; thin books 3mm, medium books 5mm, thick books 7mm or more. Before printing in volume, take a sheet off the press and fold and trim accurately to size; this is an excellent guide to seeing how the book or section will look before the job is run off.
With several sections, these can be placed inside each other and viewed to see that no positioning problems etc. occur.
Gutters
Covers over 135g/m2 paper may need to be scored to avoid cracking. Landscape books require more trim at head and tail, especially if bleeds are used; no less than 7mm per page top and bottom.
If necessary, increase the edges of the print that may bleed and possibly join them rather than leave a white gutter. Also with 2-up work, do not allow a white gutter between copies if they bleed.
On all sections allow the back half (when folded) at the foredge, to be at least 6mm wider than the front half, as this allows the finisher to feed more positively and at greater speeds.
On smaller books the position of two wires can be a problem, the allowance for each wire is 1/2″ and the minimum space between 1 3/4′ giving an overall 2 3/4″ (70mm). Trimmed minimum sizes are for 1-up, 148mm x 75 mm and for 2-up 100mm, 75mm. The maximum size is 470mm x 300mm with a maximum of 6 stitches. Paper trims should be no more than 30mm at the head and tail with 35mm on the foredge. Although certain machines can cope with up to 50mm of time (head, tail and foredge). It is, however advisable to check with your finisher first.
Max Size: 340x305mm
Minimum size: 98x85mm