I have been asked several times about how to prepare raster and vector files for print, and here is the answer:
A – Preparing Raster files for print:
Adobe Photoshop is a raster based program, and files must be scanned or created with enough resolution to support good quality output. If files are generated without enough resolution, raster output may appear to have jagged edges, stair stepping, and poor image quality.
Preparing Artwork Files that do not contain type or extremely fine-line detail should be created or scanned at 200 pixels per inches or higher. Files that do contain type or other fine-line details should be created at 300 pixels per inch. You have to note that most small type elements (under 24 pt) are best handled using a program other than Photoshop. Adobe Illustrator, Corel Draw and other vector based programs are recommended for type.
B – Preparing Vector files for print:
Adobe Illustrator and Corel Draw are used for vector based graphics, logos, and type. Unlike Adobe Photoshop, Adobe Illustrator is resolution independent. This means that artwork may be blown up to any size without getting stair stepped edges and poor resolution. The image will retain its original quality no matter if it is very small or extremely large. Note that a way to avoid font issues is to convert them to paths (outlines). Files that contain placed raster images should be linked and embedded in the final files for output.