First, Check with the sign company or your service bureau for specs like preferred resolution, due dates, material restrictions and file type.
You have to remember that large format prints are meant to be viewed from a distance. And that a large file size will make it difficult for your or your printer's computer to handle.
Illustrator , InDesign or Corel Draw is the best bet to use for small, easy to transfer files and sharp final products because a VECTOR output is much smaller and scale seamlessly without loosing quality. When working with large dimensions, bitmapped images done with Photoshop are going to be enormous (we’re talking maybe 300+ MB). Not to mention the frustration of slow opening of files as well as the likelihood of your computer crashing... lol.
But since you mentioned you'll be using CS......
If your computer can't handle the strain of a full size image, it will be safe to do the work image at half the size and at 150 - 200 PPI. TAKE NOTE... Pixel Per Inch. Take into consideration at what distance will the finished product be viewed from. For instance, if the 10 x 12 banner will be viewed from 10ft or more away, I'd create the image work in full size at 100ppi. Unless there are photos or images with fine detail, go for 150ppi. Like I said, don’t worry about this low resolution because it will be viewed at a distance. This also another reason why I'd do the work in a vector program. an image saved in a vector file format keeps it's quality even when scaled up or down (to at least 25% original size)
In preparing the file for your printer, Save the image as TIF or EPS (depending on your bureau's preference) . And don't ZIP the tiff files. The compression may affect the image.
I never send by email. Sometimes the upload and download causes problems on the image for me.
Include the psd (I usually do in case the printer has difficulty with the tiff) and include or imbed (if done in Corel Draw) the necessary fonts.
