Preparing your own design and artwork for professional litho or digital printing is quite a bit more involved than preparing jobs for in-house desk-top printing. There are several reasons for this but the main ones can be summarised as:
- the professional printing industry, as you might expect, uses professional standard software, written in its own industry-standard language (PostScript) which is designed to give reliable, high quality results. Not everyone has this, or can afford it;
- the resolution (density of image and graphics information) needed for digital and litho printing needs to be much higher than for desk-top prints;
- the job needs to be handed over to your printer, a third party, in such a way that all graphics and fonts are somehow included in the file otherwise they might be absent or substituted in the final printed job!
Here are some guidelines to get over these, and other, artwork hurdles:
Use the right design & artwork software
Our first major tip would be to start off using professional design and artwork software. So rather than attempting your masterpiece with Microsoft Word or Powerpoint, you should really be using something like Adobe InDesign or Quark Express for the page layouts plus Adobe Illustrator and Photoshop respectively for any vector graphics and photographs. Of course other packages exist but those mentioned are pretty much the industry standard these days. If you do not have these packages, or the professional-level equivalent of them, then it might well be best to ask us to produce your design and artwork for you otherwise the files you supply might give you unexpected printing results.
The colour mode for photographs would usually be set in Photoshop or its equivalent.
For ‘full colour’ work (e.g. including colour photographs) all images and graphics should be saved in CMYK mode rather than RGB (the latter is for screen and will print unreliably if you use it by mistake).
For ‘black and white’ jobs printed via the litho process (it’s not such an issue with digital), it goes without saying that all text should be made in a single ‘black’. No additional ‘spot blacks’ should be in the file’s colour palette otherwise you may accidentally use more than one black in your job and that could over-complicate the printing output requirements. Any tints should be tinted percentages of your single black. Any black and white photographs should be saved in greyscale mode.
For ‘spot colour’ work (destined to be litho printed) care needs to be take to confine all elements to your limited spot colour palettes, or tints of them. Preparation of photographs for use in spot colour jobs will vary from one artwork package to another so do ask us if you need guidance on an individual basis.
It is worth noting that the colour space for jobs destined for digital printing is a lot more forgiving then litho, should you get it wrong (and, of course, it’s quick and easy for us to output a single digital print for you to check before you commit to the full print run. That’s not so straight forward with litho).
Resolution for all photographs and any ‘bitmapped’ graphics should be 300dpi (dots per inch, also known as PPI or pixels per inch). More is OK, within reason (you don’t want the file size to be too huge) but if you supply images at a resolution of less than 300dpi a point will be reached where you start to see pixels in the final printed output, which is a bad thing! This point is usually evident at resolutions below 150dpi or ppi. For this reason, images taken from websites (usually 72dpi) are not of sufficient quality unless, of course, they are vastly reduced in size (and the colour mode changed accordingly of course – see the Colour Space section above).
How about resolution for vector graphics? Well, that’s a trick question because vector graphics (produced by such packages as Adobe Illustrator) do not have a resolution; they are made from mathematical ‘vectors’ and as such can usually be scaled to any size without loss of clarity and sharpness. If prepared correctly and used in professional layout software packages like InDesign, they simply do not have any pixels or resolution to worry about. Do watch out for those colour modes though (see Colour Space section above).
Preparing your artwork file for handover
In the ideal world you should convert all fonts to ‘vectors’ (or ‘outlines’ as they’re known in the graphic design and print industry). However, before doing this, make sure you save a back-up copy of the job when its text is still ‘live’ (editable) in case you subsequently spot an error and need to edit the text again. Outlining text means that you literally convert the text to those mathematical vectors mentioned above. Why? Because then we, your printer, do not need to have the same fonts as you, nor do they need to be embedded in the file (’embedding’ fonts is another good option but is not quite as reliable as outlining, although that does depend on which software package you are using).
In professional packages like Adobe Illustrator and Adobe InDesign, you outline text simply by selecting it with your pointer tool then choosing ‘Create Outlines’ from your ‘Type’ menu. A good way to test whether you have missed anything is to then go to ‘Find Font’ (also in the ‘Type’ menu) and see whether this handy tool finds any stray or unconverted live text – it’ll even show you where it is if you ask it to.
In most professional design and layout (‘page make-up’) programmes, externally produced graphics such as photographs and vector graphics are brought into the layout, but are not incorporated in full into the actual file. They are usually only linked to, by default. This is an important factor to take note of because if you then try to supply your single artwork file to your litho or digital printer, without all the linked graphics, then the job will be full of spaces where the graphics and photos should have been. For this reason the very best option is to ’embed’ the graphics and photographs into the final, single, artwork file. In InDesign and other similar packages this is simply a case of either selecting each graphic one by one and then using the ’embed’ command (in InDesign and Illustrator this is on the Links palette) or, easier still, allow the graphics to be automatically embedded in one go by outputting the artwork as a repro-quality Acrobat PDF file (more about that below).
Making sure about bleed:
Make sure any images and graphical elements which you want printed to the very edge of the final printed job include an extra 3mm of ‘bleed’ (i.e. they extend outside the final cropped document area by that amount). This safeguards against inaccuracies in cutting and ‘page creep’ which occurs in multi-page magazines and books, for example, but let’s not get into detail on that other than to say you do need 3mm of extra bleed for any item printing to the edge of the final job — that is an industry-standard requirement.
Saving off a PDF
Once all your fonts have been outlined and all graphics, resolutions, colour spaces, bleed and so on have been carefully checked, you are ready to output your final ‘one piece’ artwork file. Some page make-up programmes have a ‘pre-flight’ checker which, as the name suggests, checks your set-up one last time before handover to your printer. Sometimes this can throw up small issues that you didn’t think to check or perhaps overlooked. When any such issues have been sorted out, you are ready to output your final repro-quality PDF file, the preferred file type in the printing industry.
Professional page make-up programmes like InDesign do this via the ‘Export’ command. Here you save off a new file (a repro-quality Acrobat PDF file) and carefully check the settings, screen by screen. It’s very important to get them right. For litho and digital printing, high-end packages like InDesign will have a pre-configured ‘Press Quality‘ setting which you can usually choose from a drop-down list when exporting. This will set most of the export settings correctly, however you might need to check a few. For example, for the ‘compatibility‘ setting we tend to stick with ‘Acrobat 4 (PDF 1.3)‘ which is backward compatible to be safe. The best PDF ‘standard‘ option to use is usually PDF/X-3, however if your job is litho with spot colour then use ‘PDF-X/1a‘ instead. Make sure you remember to add printers’ marks and 3mm bleed during the export configuration. For the ‘Colour’ setting set it as CMYK for full colour litho and digital printing or, if there are any spot colours, select ‘Leave unchanged‘ assuming you have set the colours up correctly as outlined earlier in this article. Always open up and carefully check your PDF before handing over to your printer. Zoom in on images and check that they are nice and clear without noticeable pixels when viewed at true size and even a little larger (within reason – pixels will show, of course, if you zoom in really close). Make sure there is bleed on appropriate graphics and images which extend to the document edge etc.
When preparing your final print-ready PDF file:
- Save your images in CMYK mode at 300dpi;
- Add 3mm of bleed to your artwork, along with crop marks;
- ‘Flatten’ your artwork using the ‘Medium’ setting;
- Embed fonts or, better still, outline (vectorise) them;
- Save your file with ‘PDF/X’ and ‘Press Quality’ settings.
Southside Print in London Bridge can help you with all your printing and document duplication needs; we are litho printers, digital printers and large format printers and our SE1 location is perfect if you are looking for a printer close to locations like London Bridge, Borough, Bermondsey, Elephant & Castle, Waterloo and Southwark, just South of the River Thames. Contact us here for more information or a no-obligation quotation — we’d be delighted to help.