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How to Use Pantone Spot Colours in Print…

The unexpected combination of design, colour & print finish, and choice of paper for the front cover of GSM10 created a result with a difference. Sometimes a little experimentation can create surprising results…

For the cover of GSM10 we used a textured uncoated paper, BJ Ball Advocate Linen, on which we printed two spot colours – Pantone 876 (Metallic Bronze) and Pantone 804 (Neon Orange). Combining fluoros and metallics on an uncoated paper is usually a big “No No” but pushing the boundaries can create something special..

Replicating the Cover of GSM10

Advocate Linen is an uncoated textured paper from the BJ Ball Specialties range. Its tactile nature adds to the message communicated to the reader. Thus making it ideal for clothing swing tags, business cards, folders and catalogue covers. Like many of the Specialties range, Advocate Linen is essentially a premium uncoated paper stock.

For the cover of GSM issue 10 we did something that traditionally, you’d probably not do. We ran high-vibrancy Pantone inks on an uncoated stock. Why is this unusual? Well, normally high vibrancy inks work best on a Coated stock.

The main difference between coated and uncoated papers is the coating. Coated papers have a clay coating applied to their surface. This acts as a barrier for the ink to sit and dry on top of the paper rather than absorbed into it. This, coupled with the coated finish reflecting more light, enhances the colour and creates a more vibrant, brighter print finish. If you want a metallic or neon to really print ‘true’—then you would only ever use a Coated stock.

However, by combining these inks with a premium speciality stock such as Advocate Linen, we produced a very different effect. The metallic no longer looks ‘metallic’, but takes on a dusty shimmer instead. The neon is no longer a high-vis highlighter colour. Instead the ink beds-down, but still produces an intensity that is unusual for a colour on an uncoated stock. Add to this, the fabric texture of the paper and the whole combination produces a look that is immediately different to most other printed material.

Anatomy of the Artwork

We produced the cover artwork in Adobe Illustrator. Setting up artwork of this kind, that uses Pantone Spot Colours, requires some technical knowledge within Illustrator as well as some understanding of the print process and how it works. Here are some key points using GSM10 cover as an example.

Colour Mode:

Firstly, regardless of whether you use SPOT colour or CMYK, you should always set up the print artwork files in CMYK Document Colour Mode (under > FILE menu). Files set up for print in RGB Document Colour Mode are a potential disaster. We set this file up in CMYK Document Colour Mode.

Bringing in SPOT Colours:

Spot colours are not CMYK colours and do not relate to the CMYK print separation process. To use SPOT colours in an Illustrator or Indesign file, add the colours to your Swatches list by going to Swatch Libraries > Colour Books (under WINDOW).

We used two Spot Colours in this artwork. As part of our studio best practice we also removed all unused colours from the Swatches menu. Our Swatches menu looked as per figure 1.

Trapping:

Trapping is the term for making an allowance on artwork for slight mis-registration on a printing process. To create a Trap apply a fine overprinting keyline around a coloured object where it overlaps a different coloured object (see figure 2).
In CMYK printing, most trapping happens automatically because the Black plate, which prints last, ‘Keys’ (the ‘K’ in CMYK) the other three process colours (CMY). We achieved this by overprinting them.

When working with SPOT colour, Trapping is a necessary consideration. It can be set manually by applying a thin keyline (0.3-0.4pt is usually enough) around objects that use the spot colour and setting this to overprint. (Go to WINDOW > OUTPUT > ATTRIBUTES > and tick the OVERPRINT STROKE selection). Do not accidentally tick the OVERPRINT FILL or you’ll get some very unexpected results on press.

In our case, we have two spot colours, so we only applied the trapping to the spot colour that will print last (in this example PMS804 Neon Orange).

You can check your trapping by turning on the OVERPRINT PREVIEW. (Go to VIEW > OVERPRINT PREVIEW). This mimics the expected print result. What you should see is a thin dark keyline where the Trap is set (see figure 2).

GSM10 spot colour separations

Preflighting:

It is often a good idea to preflight artwork files that contain Spot colour. The easiest way to do this is to create a POSTSCRIPT file of your artwork as print separations—and processing the POSTSCRIPT file in ACROBAT DISTILLER (part of the CC / CS family). This will create a PDF file of the separations that you can review in Acrobat Pro or Acrobat Reader.

In our example, our SEPARATIONS looked like the simplified examples shown in figures 3 & 4. In this example there were only two separations as CMYK is not used in the cover artwork.

Words OF ADVICE:

Some of this might sound really complicated, especially for people new to the industry. If you are producing projects that use SPOT colour, we recommend speaking to the pre-press department at your printer or getting your production manager (if you have one) involved early in the process. The pre-press department at your nominated printer may actually do a lot of this work for you, but it helps to understand the basics around artwork using SPOT colour.

This article was originally published in GSM10. To read this and other great articles purchase this issue here.