We accept most popular file formats. However, it is best to export all artwork to a PDF. This reduces any issues of us not being able to open someone's file if they are using a non-popular design program. Have no fear though at 4OVER4.COM we're here to help. If you're not sure if what you did is printable, send us your files and we'll examine them Free of Charge. At no cost or obligation to you, we'll have one of our professionals at 4OVER4.COM review your files. We'll let you know if there is anything that will prevent us from printing your job. If we find everything to be in order, we will put a proof online for you free of charge. Even if there is something wrong, we will email you what the problem is to help you fix and revise your files. Please keep in mind that submitting files that do not follow our proposed guidelines will delay your free online proof and subsequently, receipt of your finished order.