There are numerous types of digital barcode file formats. For book cover design, ALWAYS use vector-based .eps barcode files for accuracy and precision. Even though some file formats might look crisp on the web, the barcodes used for replicating barcodes on the back covers of books needs to be accurate for printing.
Encapsulated Postscript Files (.eps)
EPS is a file in vector format that has been designed to produce high-resolution graphics exclusively for print. EPS files essentially contain a series of instructions for how a printer should reproduce an image at the maximum resolution. These files are the print industry standard format and can be imported or inserted with most graphic applications. Although they are the best format for barcode images to be printed, EPS files cannot be used for web graphics.
For a complete explanation of various barcode types, please visit: