Although many printing companies will accept nearly any file format you can give them, there are still some companies that have preferred file formats and specifications. When choosing to work with a printing company, it's important that you prepare your digital files in a way that your printing company can use them. For many printers, it's as simple as saving your digital file as a PDF (portable document format). This format of file contains all the information (graphics and fonts) that a printer needs to produce your file, and is easily opened on any computer. PDF writers are now open-source (free) so it should be easy to download one that will suit your needs. Another way is to ask the printing company what file format they want, and use that format if possible – this will save you time and trouble in the long run.