What are crop marks and bleed? A quick guide explained
There is a lot of terminology in commercial printing that unless you are an experienced graphic designer may seem alien to begin with. This article focuses on how the role of crop marks and bleed are used to ensure perfect printing results.
Crop marks and bleed play a role in the origination stages and therefore must be taken in to account during the final stages of artworking. The marks are then added to the artwork and printed at the corners of each page.
Introduction to crop marks and bleed needed?
Commercial printing presses are not capable of printing to the edge of a sheet of paper – they are printed on much larger sheets of paper than the final size required. In most instances multiple pages are printed on one large sheet and then trimmed down to the desired sized after printing. To trim the sheet to the desired size requires crop marks and in some instances bleed.
What are crop marks?
Crop marks are lines printed in all 4 corners of the printed sheet – there role is to indicate where the sheet should be trimmed to achieve the desired size once printed.
Whilst they have the name crop marks they are also known as trim marks or cut marks.
Professional publishing software software such as Adobe Indesign is able to output these on artwork produced by the graphic designer, they can also be added by pre-press software.
What is bleed?
Sometimes there are design elements that require images, colour and other design features to fit right up to the edge of the page. To ensure a floorless finishing during the trimming process the designer will extend the design by an additional few millimetres beyond the crop marks – the term know as bleed. This ensures when the sheet is trimmed that it cuts through this 3mm creating as design that prints right up to the edge.
Once the sheet has been trimmed the document looks as pictured below.
What happens without bleed?
Without bleed there is a risk that any design elements that boarder the crop marks could end up with either a slight white line around the edges when they are trimmed, or a small part of the design may be cut off. This is due to the fact that there is a tolerance on guillotines used for trimming of approx. 1mm in either direction – adding bleed will overcome this.
When bleed is not needed
There is no need to add bleed if the edges of the design are surrounded by a white background, as it won’t affect the design during trimming as shown below.
Minimum boarders for artwork
It is recommended that any text, keylines, images are kept within a minimum of 5mm of the edge of the design, this will ensure no part of the design is too close to the edge of the page during the trimming process.
More about how to set up artwork ready for print is available here