Underprinting

We are in the process of producing a brochure for a new client. It's the first time we've worked together and they are a little nervous. They’re investing time, energy, money and reputation to work with us and we want to ease their concerns.

Their main concern is achieving correct colour reproduction of a corporate colour onto coloured paper – namely a strong deep blue printed on a bright pink board. Now colour, or at least colour in print, is when light travels through ink, bounces off a substrate (paper, in this case) before being reflected back to the eye. Colour, like love, is often in the eye of the beholder, which is why all good designers and printers refer to a common colour language such as the Pantone colour system and often use densitometry or spectrophotometry to calculate the accuracy of a target colour. However, most (but not all) inks are transparent. Therefore the paper coating, texture and colour can dramatically influence how the ink colour is perceived.

Knowing this, consider that some inks are opaque and unaffected by the color of the paper. Opaque white is exactly that – an ink which does not reflect light – and we can use it to our advantage to accurately reproduce ink colour on a coloured paper. This is how it’s done:
 

1. The client’s corporate colour is printed in opaque white onto the bright pink board    
2. To achieve an obliterating opacity the opaque white might be printed twice in one pass through the pass   
3. The printed sheets are left to dry    
4. Once dry, the sheets are fed through the press again, this time with the corporate colour overprinting the pre-printed opaque white
5. The sheets are left to dry again, before being made up into brochures and delivered to a happy client
6. Factor in the cost of a wet proof and you’ll understand why underprinting isn’t cheap but neither is it commonplace. The technique can be used to achieve some unique and intriguing design effects; a beach scene, for example, printed in black half-tones on a grey board underprinted with an area of opaque white might give the illusion of that area being bathed in sunlight. If you would like to bring some underprinting into your work, you know where we are.