Ad Printing Specifications:-
http://www.ppa.co.uk/all-about-magazines/production/proof4press/
We are a perfect bound product. For single pages – a minimum of 2mm text and image will be lost in the gutter and therefore we advise that all text is kept at least 5mm away from the trim edges (to be entirely safe all text should be kept within the Type Area). For double page spreads – when running text/images across the gutter, a 3mm double image allowance on each page is advised in order to prevent any loss of live matter into the gutter.