Bleeds for dummies, or in other words: back to the basics

Preparing a file for printing is not easy, which is true particularly when you are lacking experience. And the absence of bleeds claims the dubious honour of ranking first amongst the most common mistakes made in this regard. However, worry not: it happens to the best of us, even professionals with many years of experience. The only real issue arises when you have no understanding of what bleeds actually are. Again, fear not: we will help you see that in effect bleeds are not a menace, but a safety margin.

Practical implementation of bleeds

This is one of the simplest exercises that old dogs use to show their less experienced colleagues what bleeds are for. What you do is take a pair of scissors and cut out – as accurately as possible – a black rectangle of certain dimensions printed on a sheet of paper. You have to be precise and make sure that not even the slightest sliver of black is left on your sheet of paper and the rectangle in your hand shows no white whatsoever along its edges. The result is always similar. You cannot do this flawlessly despite your best efforts. Now, if you – with your careful eye and nimble-fingered hands – have failed with one single sheet of paper, you cannot expect a machine to fare any better. Still less when, for instance, you consider that a paper guillotine does not take a few minutes to cut one piece of paper; on the contrary: it cuts several hundred sheets simultaneously. So, what can you do to ensure that your rectangle does not have a white frame, and – at the same time – does not diminish in size once cut out? You can add a few millimetres of a safety margin on each side, which you can later cut off without concern. And this is exactly what bleeds are!

The theory behind bleeds

A bleed is the part of your image over the net size removed when you trim your printed materials. This definition, despite being short, may be difficult to grasp. The net size is the one you want to arrive at in the end. The gross size is what you have before trimming, that is, before cutting off your bleeds.

GROSS SIZE less BLEEDS equals NET SIZE

When do you use bleeds?

When you want an element of your design (such as images, background, graphics) to reach all the way to the edge of the sheet. This way, you will be able to avoid an undesired white frame showing along the edges of your page as a result of any micromovements happening during operation of the guillotine, the printing machine, or even the positioning of the sheets of paper themselves.

And what about the width of your bleed?

The norm here is between 3 and 5 mm. This will depend on the printing house and the requirements of the respective stock of machinery. If the printing house does not clearly state the width of the bleed – ask! This will save you time. At our printing house, we prefer bleeds 5 mm wide (there is more to learn about bleeds from our Guidelines for preparing materials for digital printing).

How do you set your bleeds using graphics software?

For more detailed information on how to create a document allowing for bleeds using specific graphics software, be sure to watch our video tutorial. Good luck!