Preparing Artwork Files for Offset Printing whilst Avoiding the Pitfalls

There are two very different skill sets required in producing artwork for printed products. Not so long ago a graphic designer and an artworker were totally different roles, but today’s designers need a good understanding of what is required to take a creative concept through to printed completion, avoiding all the possible complications.

 

Choosing the Right Software

Using professional page makeup software is the first, and most important, step in the process. Adobe products such as Illustrator, Photoshop and InDesign and others such as QuarkX Press are the industry standards and have an established track record for creating professional, print-ready files.

There are a host of free programs or cheaper options than these packages but, if you are after consistent, well-produced results, stick with the software all offset printers will have and use every day.

If you are unsure as to how to prepare your files or set up a particular aspect of a job, speak to your printer’s pre-press department and they will happily talk you through it. In fact, speaking from experience, the closer the relationship between the designer/artworker and the pre-press department, the smoother the process will run.

 

 

Prepare Artwork Files for Offset Printing

Avoid the free software that comes on your PC or Mac. Yes, it will work fine for some invitations to your Christmas party printed on your own home machine, but for producing decent, print-ready PDFs, forget it. Invest in the best. Word, Publisher and others may be widely used but they are not designed for professional printing work.

Color Variation between a Monitor and Printed Paper

If you are new to preparing artwork for printing, there is a lot to learn!

First of all, dismiss from your mind the idea that what you see on your computer screen in glorious technicolor will be what appears in print nicely packaged a few days later in your office or on the doorstep.

Unless you have a good grasp of the influencing factors, you may be disappointed with the results. A good offset printer will have run your files through various checking procedures known as pre-flight. This will highlight any potential irregularities and the system may reject the file.

Please note that some of the cheaper online print services will just produce whatever you send them. There are simply not the financial margins to highlight any issues to the customer.

 

Color (or Colour) management is crucial and a difficult area to fully understand, even to those with plenty of experience in the trade. Not so long ago this meant producing Photoshop images with various color profiles attached or embedded that carried this information through to the RIP (Raster Image Processor).

This interprets the file information and converts it via Postscript into a format that can be output to various devices including plates for offset litho. Luckily you don’t actually have to understand how this all works.

 

CMYK and RGB

You may notice that the major software platforms work in various color spaces.

All you really need to know is that RGB (Red Green Blue) is the additive color space for anything produced for and viewed on a screen. CMYK (Cyan Magenta Yellow Black) are the basic inks used in the subtractive offset print process.

Therefore, make sure you are working in CMYK when producing images in Photoshop or similar graphics packages.

Note: Photoshop and other image software normally work in RGB as a default, so you will have to convert your files. There are two other important factors to be addressed when using images in your project.

 

High-Quality Printing and High Resolution Photos

Resolution; this is the pixel count or dpi of the file. We have all seen examples of low-resolution images being printed, and they look horrible. The problem is that a computer monitor, phone or other devices, only requires a resolution of 72dpi for an image or text to look sharp and clear.

Offset printing, however, needs your images to be 300dpi, and this is if reproducing at 100% in the software. If you are enlarging the image in your program, the proportional resolution will drop accordingly.

For mono bitmap line drawings and graphics, the resolution may need to be nearer 1000dpi for accurate reproduction. If all this seems complicated, well it is, but if you ensure your images are CMYK and 300dpi, you are heading in the right direction.

Your files need to be saved in certain formats, for example, EPS, JPEG, TIFF etc. The differences between these types and why and when to use them are the subject of a different article.

Basically, the various formats retain different information, much of it not really visible to the eye. JPEG files compress the data, creating much smaller files but losing some of the color information and detail.

Modern RIPs and page make up software sort out a lot of the problems for us now; files that wouldn’t have worked a few years ago can now be processed, although the results may vary.

 

As with images, imported graphics such as vector logos and anything else not created in the software itself need to be CMYK as well.

An established brand will have RGB and CMYK versions of its graphics available for various uses. Your local plumber may not, so beware.

If using InDesign, Illustrator or QuarkXPress, set up color breakdowns in the job as CMYK for the best results. So far, reasonably straightforward.

 

Pantone Color Printing

One of the areas that commonly cause problems with offset jobs is where special colors, spot varnishes and other no CMYK features are involved.

For example, a client’s logo needs to be printed as a special Pantone color rather than out of CMYK. However, it may have been supplied as an RGB file that will print in totally the wrong color. Or the Pantone reference number in the supplied file may not match with the Pantone number in InDesign.

It will look alright on the screen or even print well on your office printer, but may not separate correctly at the pre-press stage. The only way to check this is to open every element of the job in its native format and make sure each aspect is correct.

If you are setting up elements of a job for spot varnishing or foiling etc, please consult your printer’s pre-press department. This is a potentially complicated area and the initial job set up is crucial.

 

Rich Black Ink Set up

The design of the print project can have an impact on the final result as offset printing does have certain limitations which can mean results can vary.

Heavy ink loads on dark solid colors can cause issues as can the reproduction of some gradients and vignettes. Solid black printing, in particular, needs to be set up correctly in the first place to ensure a rich result.

There is a reason why CMYK printing is generally cheaper and that is it is a simpler process in many ways. Everything is separated into the four process colors and then recombined on the presses. As soon as other separations are required, the process becomes more involved.

 

Once you are happy with the design of your project and the artwork is complete, you need to produce print-ready files.

InDesign, Illustrator and Quark have pre-set to create high resolution, print-ready PDF files. These will include the appropriate bleed and trim marks required by the print company.

Speak to your printer and they will advise you as to which to use for trouble-free output.

 

If you have not produced artwork for offset printing before then all this can seem pretty daunting. However, you don’t really need to understand how it works in detail, just how to implement it all in your design and artwork.

Once you have created a few print-ready files it will become second nature. The bottom line is to use a professional print company, who will be happy to guide you through the process to ensure a smooth passage through the factory and a print job that meets or exceeds your expectations.

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