There are different factors to be considered when preparing large-format graphics for printing trade show displays. The traditional rules of file resolution used in standard offset printing may not apply. A common misconception is that higher resolution automatically yields better quality printing. This is not true for large-format printing, except that it produces a huge file that is often impossible to edit or transfer. Here is why.
For business cards, brochures, magazines, etc, the distance from the viewer to the media is much closer and the dots that make up the image become much more easily visible at a lower resolution. A standard of 300 dpi (dots per inch) is usually required to ensure high quality print-outs and avoid noticeable pixelation. For large format printing, the standard is much lower to accommodate for the large space to be printed, the distance from the viewer to the display, and the capability of the printer.
The minimum dpi for a large format graphic display is typically 100 dpi. We have found this to be a good compromise to accommodate a client’s images, file sizes, and final output. This also helps our clients to understand what size of file they will need when purchasing from a stock library.
For instance, if you have a 10' pop up display (154.72”wide by 88” high) and wish to use one large image for the background, at 100 dpi your image will need to be 15472 x 8800 pixels or larger. If you were to use 300 dpi as opposed to 100 dpi, the image would need to be 3 times the size (4500 x 4500 pixels) and the file would be much larger.
We will always do our best to review files that are submitted and inform the customer of any potential issues with the resolution, but if all of our Artwork Guidelines are met there should be little room for error.
For more tips and help regarding images, check out our article regarding large format image gathering.