Designing for professional printing

We’ve already discussed the growth of digital publishing, but professional printing is required whenever you need the highest quality hard copies, to print on special materials, to make product packaging, or produce large format/large volume prints. And for bigger print runs professional printing can be cheaper than using regular office equipment.

Whether you are taking your print file to your local print shop on a USB stick or sending it to an online print service, there are some things worth knowing that can save you time, trouble, and money.

Professional Print Quality

Layout

Bleed

Printers usually layout your job on larger paper and trim it to size, to ensure neat printing and sometimes to mix your job with others in one print run for efficiency. This trimming causes an important layout consideration particularly for edge-to-edge designs. This is something we touched on in our poster design article: if you are designing to the page edge, go further, design beyond the page edge.

This run-off area is called bleed (or a bleed area) and, although it is trimmed away, extending your design into this area ensures that trimming never leaves any unsightly ‘unprinted’ edges. Your print shop should have a specification, template, or general set of guidelines that mentions bleed area, which is usually in the range of 3-5mm.

If your artwork doesn’t run to the page edge, consider white space as an integral part of the design rather than absence of design.

Stack height (or Z-order)

When mixing text and graphics, make a conscious effort to bring your text to the top of the pile, bring it in front of graphics (unless there’s a specific need for graphics to be in front of text). The rectangular regions around irregularly-shaped graphics, or regions affected by shadows and glows, can sometimes be subject to printing oddities due to the way transparent areas are processed. If this happens it is much less noticeable when text is in front of these areas, not behind them.

Imposition

This is something the print shop usually worries about, but you should be aware of it. Your job might be small, like a business card, but the print shop will layout many copies of your business cards on very large sheets, perhaps even mixing your work with that of other clients in one print run. The issue is more important if producing folded multi-page documents, as the page order is likely to be different in print compared to the on-screen design. As mentioned, the printer normally handles print layout changes without bothering you, but you may be requested to enable or disable Impose pages in the Publish as PDF dialog to suit their needs.

 

Colour

Colour models and systems

There’s no easy way to say this, but it’s almost impossible to get accurate printing of on-screen colours. We’ll go into accuracy in a bit more detail below, but in order to understand colour for pro printing purposes, know that your screen and printout make colour in very different ways. Your display mixes red, green and blue light (RGB) to make a massive range of colours, while print presses make colour by blending cyan, magenta, yellow and key (black) inks (CMYK). It’s the difference in technology between screen and print that gives rise to visible differences in colour between the two media, but you can minimize the discrepancy by designing using CMYK colours in PagePlus.

CMYK colours

The CMYK inks used by printers can blend to make 100 million different shades. While this represents more graduation than the 16.7 million colours produced by typical computer screens, CMYK inks are notably less vivid than on-screen RGB colours. You’ll see this when you look at a CMYK palette in PagePlus – it is meant to look duller than RGB palettes, because it’s representative of what CMYK inks can produce. Although muted in nature, it’s best to use CMYK colours in your design if you’re designing for print, but whether you use RGB or CMYK PagePlus can output correctly using a print-shop compatible format.

Single colours (spots)

There are other single-colour inks available to you, called spot colours, which can be very bright and even incorporate special visuals like metallic sparkle, and you can use any spot colour to represent these in your design. Each ink or spot colour used will require a print run and drying time, so consider this as a cost factor if using CMYK and spot colours in one job.

However, if your artwork is only one- or two-colour, you can skip using CMYK and just stick to one or two spot colours instead. Pantone® is a popular international colour system for spot and CMYK colours, with printers using branded inks or calibrating their systems to create consistent colours, so using these palettes in PagePlus is one way you can predict the results quite well. Check whether your printer can offer Pantone CMS, Pantone Goe, or Pantone PLUS choices, based on CMYK or spot inks as appropriate; they are all available to use in PagePlus.

Accuracy

As mentioned above, the limitations of printing technology mean that most “full colour” printing is much less vivid than on-screen colours. You can use CMYK palettes to reduce the difference between on-screen displays and printed results, but if you want them to match even more closely you can set up your design process and Windows system further.

Start by installing a colour profile for your display, and finding out what the output profile is for the print job (information your print shop can supply that describes their systems, e.g. “FOGRA 39”). The profiles takes into account the way colour is handled by your monitor and the print process used by your print shop, so the colours on screen and in your PDF file better match each other. Enable colour management in PagePlus X6’s Tools menu, choose a suitable monitor and output profile, and set the same output profile as the Output intent when publishing your PDF/X-1a file (in the Advanced tab). Learn more in the PagePlus colour management help topic and at www.icc.org.

If you do not have an ICC colour profile for your screen and want to achieve some colour precision, you can calibrate your monitor using a specialist service or a device like the Pantone hueyPRO, SpyderPro, or ColorMunki Display.

Images

Images are made of either RGB or CMYK colours. If you’re not sure which you are using don’t worry, PagePlus X6 will do a great job of converting RGB images to CMYK automatically when you output your PDF/X-1a file. When you see a professional CMYK image on screen in your design, it could have an overall duller tone or even be represented by exaggerated colours, both of which can appear inaccurate, but it should print well.

Text

As recommended above, you should use CMYK colours in your design, but please bear in mind that each ink typically has its own print run. For smaller font sizes, this can mean blurriness or colour-run due to registration issues (the print runs not all being perfectly aligned with each other). Try to keep text set to one or two ink colours, for example mixing 100K and 20C to make it slightly darker and richer than black ink (100K) alone.

You can set text to automatically overprint black on top of the colour of underlying objects, making it appear richer without risking the misalignment issues described above. In this case, dark text need only be 100K (black), not a combination of CMYK colours. Set overprint black text is an output option in the Prepress tab of the Publish PDF dialog and is checked by default when you output using the PDF/X-1a publish profile.

When black isn’t black

As hinted at when discussing text colours, black ink is not actually black. The K of CMYK comes out a dark grey when printed on its own, a less dark black than we typically see on our RGB monitors. You can compensate for this lack of depth by combining some other CMYK inks with the black, e.g. 30C, 30M, 30Y and 100K to make a rich black. This darker colour is available in the PagePlus CMYK swatch, so be aware whether you’re using this richer type of black or the duller single-colour black of 100K.

You can change the appearance of black in your design, choosing whether to display blacks accurately or as the darker rich black. This option is in Tools > Options > Drawing Quality > Appearance of Black.

 

Image quality

When using images in professional printing circles, you’ll often hear the term resolution. “What resolution are your images?” or, my favourite, “What resolution were they saved at?” When you’re creating, editing or saving an image, resolution is pretty much an obsolete term. The resolution value is saved with the image as a simple piece of text information embedded in the file, it does not affect image quality in the slightest. What really matters is image size, in pixels, and whether that size is suited to its intended use – basically, you need lots of pixels to print images at a large size and at nice quality. How many pixels? 300 per inch (just count one dimension, not both). But even then, if you’re printing a canvas to attach to the side of a building, nobody’s going to be able to see the fine detail, so you can afford to stretch images further.

As an example, if you’re using an image that is 3000 pixels wide and 2000 pixels high, it’s suitable for inclusion in a typical print design at 10” wide x 6.7” high. If you want the same image to be bigger on the page, try to avoid stretching its pixels too far by staying above 200 DPI (reaching a maximum size of 15” wide x 10” high in this case). If you take images beyond that level of stretch, you’ll see jagginess or fuzziness in the printing. If you have more pixels to play with, you can place the image at a larger size, and if you have many more pixels than you need PagePlus can automatically output images in your job at the ‘correct’ 300 DPI for best results.

Resampling images

You can add pixels to an image when ‘resizing it’ or rather resampling, using PagePlus, PhotoPlus, or a range of other tools. However, this is no substitute for having an image of suitable size to start with, as the science of adding pixels can only go so far in maintaining quality. You may notice a slight blurring using even the most advanced methods.

If you are using images in a vector format e.g. SVG or WMF, they will always be output at the right quality because they are made of lines, shapes and fills that easily scale, unlike the fixed nature of coloured dots in photo-style images.

Other considerations

When placing or resizing an image on your page, keep it the correct shape. If resizing, drag using corner handles. Crop images to fit rather then stretching them to be taller or wider, squashed subjects in a photo can be very distracting and look less professional.

Use effects with care, adding shadows, transparency, cutouts and colour hues if suited to the look of your design. Note that some image effects could alter a native CMYK image to be based in RGB colours instead, but would still be published as CMYK as appropriate when you save your pro print PDF file.

There are more design and output tips in our Publishing for professional printing article!

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  1. April 2, 2013
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