Preparing Computer Graphics For Sign Printing

If you are looking to reproduce your business logo on a sign, decal, business card or other real-world advertisement, you are inevitably going to deal with the digital domain at some point. The computer is an indispensable element of graphic design these days. Many people will be familiar with desktop publishing or Photoshop, but when it comes to preparing graphics for larger displays such as signs, there are a few industry-specific things that you need to be aware of.

Vector vs. raster graphics The images that your camera takes, and that you typically find on the net, are classified as raster images. This means that they consist of pixels on a fixed 'raster' or grid. Raster image formats that you may be familiar with include JPG, GIF, PNG and BMP.

As such images have a fixed amount of pixels, they will become more grainy and indistinct the more that you enlarge them. This means that, for example, if you prepare an A4 size raster image on your screen, it may look fine printed out on a sheet of A4 but will be unacceptable as a larger poster, banner or sign.

On the other hand, a vector graphics format stores your image data as a set of mathematical equations, and you may zoom into such an image indefinitely without it becoming grainy or 'pixelated'. This means that one basic vector image can be used in applications as small as a business card, or as large as a billboard, without loss of image quality. Common vector graphics formats include SVG, EPS and PDF.

Working with vector graphics requires special software such as the commercial Adobe Illustrator or the free and open-source Inkscape. The process is very different to what you may be used to in working with photos using Photoshop or GIMP, and you may find that hiring a professional graphic designer, who has already traversed the steep learning curve, saves a lot of effort. Sign writing companies like Landells Signs often have in-house graphic designers who can provide a complete service from conception of your image to preparing it for printing, or they can advise and assist you on working with existing materials.

Finding the right graphic for your business A professional graphic designer can produce a design for your business ex nihilo or can work with the images you provide, which should be in vector form for best results. You can buy the rights to use one of the many attractive illustrations uploaded by designers on sites such as iStockPhoto, Shutterstock and Fotolia. If you find a graphic that you like on one of these sites, you can further tweak it using the vector graphics programs mentioned above, changing the colours and dimensions and adding your own text.

On-screen vs. print colour schemes The colour scheme that your computer uses is known as RGB (red, green, blue). Each coloured pixel of an image is described in terms of how much red, green and blue light is required to produce the colour, a process known as the additive colour model.

When it comes to printing out materials for use in the real world, the industry uses a standard known as CMYK (cyan, magenta, yellow, black). This refers to the proportions of different-coloured inks needed to best approximate a given colour. There is a possibility that the RGB colours may come out slightly differently when converted to CMYK, although the differences will probably not be at all apparent unless you have a trained eye.