In order to do this, the file must have a resolution that compensates for the stretching needed to enlarge it to the final size. This is because the file we print must be a minimum of 100dpi at full print size. An example of this would be a file that is 1/3 of the print size. That file would need to be at 300dpi because it must be stretched to 3 times its dimensions to get to print size. At 50% print size, the file would need a minimum of 200dpi.
We strongly encouraged any designer working at a size other than full print size to bring their file into Photoshop, adjusting it to full print size and dropping the resolution to 100dpi before the file is uploaded to us. Once it is adjusted, you can also view the quality by going to view/print size in Photoshop. This will help you determine if the image quality is acceptable.
If you still have some concerns or simply have questions about your artwork, feel free to give us a call to discuss them. We have designers on staff who can answer most of your design-related questions.