Artwork specifications for large format printing such as vehicle wraps, wall murals, banners, window graphics and other types of large format printing are quite different than the artwork requirements for print media and websites. The key to producing high quality prints is having high quality art.
There are two different types of artwork with two completely different output outcomes. The first is “vector” art. This is artwork usually created in a program such as Adobe Illustrator. This type of artwork enables you to indefinitely enlarge your prints without losing any resolution/quality. This is obviously a sign makers dream to receive these types of files from clients.
The second type of artwork is “raster” art which is usually created in a program like Adobe Photoshop. This type of artwork usually contains photographic images to produce a more realistic feel to the project. Even though this process may have a better look, it is very difficult to find the images at a high enough resolution to achieve an unpixelated look for large prints. There are however, a number of stock photo sites online (e.g. istockphoto.com) that will allow you to purchase images at really high resolutions to get the desired effect.
Most of the time a customer will not understand these concepts and will supply images/files that were found on the internet or taken with a camera phone and will submit very low resolution images and think that just because it looks good on their screen that it should be good enough to print. The best types of files for sign makers are .ai, .eps or .pdf files. A good sign maker/designer adds value to the process when he/she takes a .jpg (raster) file and converts it to a “vector” file, but this takes extra time and skill.