Like Getting Bleed from a Stone

It’s hard to draw a line where the responsibilities of a Designer end and that of the Prepress department begin; unless of course, you work in the Prepress department.

The word on the street is that it is that it is pretty clear. Designers just have to provide a file Prepress can work with. And everyone gets to live.

The best course of action is to ring your Printer and talk to someone in the Prepress department - ahead of time, ask them what they would like from you. Some Prepress departments embrace a complete Adobe .pdf [ Portable Document Format ] workflow, others are happy to receive open files. But, regardless of the file format there are a couple of things Designers should remember when creating a file they wish to have printed.

The Rule of Three

I made that up. There is no ‘rule of three’, but it may help remind you to;

    1. add a three millimeter bleed to your document
    2. make sure all your imagery is three hundred dots per inch [ dpi ].
    3. I guess there should be a third one there…

Paper Cut

I am constantly amazed by the amount of Designers that are ‘unaware’ of bleed. The concept is pretty simple, if an element engages the edge of the document, it should extend past the edge to account for movement during the trimming process. Most industry standard applications have the ability to include this area when printing, whether it be to a digital printer or to a postscript file. If the application you are using doesn’t, [ Publisher, I am looking in your direction ] it might be time to upgrade to something a little more ‘professional’.

The bleed, therefore, is tightly integrated with the size of the document and it is important to consider the final trimmed size of your project, as this should become your starting point. Providing the artwork for a business card in a document A4 in size is not a good way to make prepress friends. Especially if the aforementioned artwork it is not even remotely centred.

If a typical business card, when trimmed, measures 90mm x 55mm, this should then become your document size. Adding bleed to the document then becomes a trivial task and with that, comes the added bonus of Printer marks such as trim [ or crop ] marks, registration marks and colour bars etc. with no extra work. Including this information in the final .pdf is just a matter of adding your bleed to the document size, the print dialog box in most applications will even calculate this simply sum for you - entering; 55 + 6mm will insert the total - 61mm when you tab to the next text field - this is true of some of the application palettes also.

Colour Blind

The Printers marks added by the application also tend to be in the correct colour space - something usually overlooked by designers keen to meet a deadline. Trim marks should be composed of the colour ‘Registration’. A common misconception is that Registration is made up of 100% of all four process colours [ Cyan, Magenta, Yellow and Black - CYMK ] due to the way they appear in print. But elements marked as Registration appear on every plate - including plates for spot colours, therefore a more accurate definition would be that registration is composed of every colour your project will separate into, but in reality, elements marked as Registration are more likely added to each separated plate just before imaging and are not really ‘made up’ of any colour at all.

Colour can be a pretty subjective subject and is a tangent beyond the scope of this particular post, but when it comes to actually ‘printing’ something, colour breaks down into three main groupings. CYMK, Special or Spot colours [ with the Pantone range tending to dominate the industry ] and RGB. We touched briefly on CYMK1 in the last paragraph and is usually the important one for [ process or four colour ] printing. Special colours are also important in that they can be used to extend the printable gamut, as well as providing special finishes such as metallic or fluorescent. But it is the RGB colour mode that can be used to give the Prepress department an ulcer.

RGB [ Red, Green and Blue ] is a method of describing colour with light. Combining equal amounts of two of the primary colours produces an secondary colour [ Cyan, Magenta or Yellow ] and combining equal amounts of all colours creates white. This is described as additive colour. And it is impossible to print.

Without getting into explaining colour in its entirety, the RGB gamut is considerably larger than the CYMK gamut. Elements described in RGB need to be converted and tend to be converted automatically, based on colour profiles, during the ripping stage. This can lead to some unexpected results. Because the RGB gamut is larger, colours that can’t be reproduced with the subtractive [ CYMK ] model, while looking good on screen, will print darker and ‘muddier’ as they are converted to the smaller CYMK gamut 2. It is important, therefore, to correctly spec elements in the colour space you intend to print to avoid such mishaps.

1. Which can be technically defined as spot colours also.
2. This procedure also affects the Pantone range of colours when printing in process


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