When you upload an image to www.vistaprint.com you assert that you have appropriate rights to that image and represent that you are not infringing on the trademarks or copyrights of others. To upload an image on www.vistaprint.com you must have appropriate rights to any text or graphics that you incorporate into your products and represent that you are not infringing on the trademarks or copyrights of others. Full Bleed refers to images that extend to the very edges of the document. To prevent an unwanted white border from showing at the edge of your document, be sure to extend any background colors or design elements all the way to the edge. Create your document at the full bleed size if you are working in an illustration program (such as Adobe Illustrator or Corel Draw) or a photo editing program (such as Adobe Photoshop or Corel Photo-Paint), we recommend that you create your document at the full bleed size. This will prevent any white edges from showing at the borders after the final product is trimmed. Trim Size refers to the amount of the image that will definitely appear on your document, and is safe from being cut off. Trim size is indicated by the dashed line border on your document, which is roughly 1/8 of an inch from the edge of the document. Create your document at the trim size if you are working in a layout program (such as QuarkXPress or Adobe InDesign) we recommend that you create your document at the trim size and include the specified amount of bleed for your product (.137). When you export your document as a PDF for upload, make sure to include the bleed in your output settings so that the final upload PDF document is at the full bleed size for your product. You may also download pre-sized product templates, available for the most popular design applications. Resolution refers to the number of dots per inch (dpi), or the amount of detail the image has. Higher resolution means a more detailed image, and also larger file and longer upload time. For best results with most products, your image or photo should be 300 dpi (dots per inch) at the final print dimensions (full bleed size when uploading an entire product design). Simply increasing the DPI setting in a graphic program does not improve the resolution. T-Shirt images should be saved to at least 175 dpi at 100% of the dimensions at which they will print to ensure high quality printing results. Your images will be sized proportionally based on shirt size (default size is large). Bleed size does not apply to T-Shirts as the full bleed and the trim size are identical. We want you to love the products you order from Vistaprint. If you are worried about how your uploaded image or photo is going to look, give us a call and we'll take a look. A background image: Has text and/or photo frames, and other graphics can appear on top of it. Background images are applied to the full bleed size of the document you are creating (but you can reduce its size after uploading). A logo: Appears on top of other design elements (for example, your uploaded background image or a design that is part of the template). However, it is possible add text on top of a logo image. Remember, your photo or design must meet the required file size, image dimensions, resolution, and file format before uploading it to our Web site. See our Artwork Specifications for details. Good question. These terms are thrown around a lot in the printing and graphics world, and it is important to understand the difference. How does this affect me? Any image you create on your computer should be created in CMYK mode. This will ensure that the colors you see on-screen will most closely match the final printed product. If you create your document in RGB, the colors in your printed product may vary slightly: many of the bright values produced by your monitor cannot be exactly reproduced in print. Source.