There are basically two types of images you can send - vector or bitmap.  In most circumstances vector format is preferable, because it can be easily resized without losing clarity.  Vector images are generated with Adobe Illustrator or CorelDraw, (and there are a handful of other vector drawing programs as well).  These file formats would be .ai (Adobe Illustrator) .cdw (CorelDraw) or .eps (encapsulated post script which is not the name of a program, but of a vectopr file type that is generally compatible with vector drawing programs.  For most orders we use Adobe Illustrator and that is the file format we prefer to work with. You may also save your file to the .pdf format (this is handy if you are using a word processor like Microsoft Word).   If you are using CorelDraw, then we ask that you please save your file in Adobe Illustrator format (.ai) before sending it to us.  For bitmap images, Adobe Photoshop is the main program which outputs images in a variety of bitmap formats such as .jpg, .png, etc.  If you only have a bitmap image, save it in the highest resolution possible before sending it to us.