The higher the resolution of the scan, the larger the file size. Use these guidelines to optimize your images.

Scanning at Actual Size:

Resolution Settings	Dots Per Inch (DPI)	Use
Low	72 dpi	for web viewing
Medium	150 dpi	for printers (laser or ink jet)
High	300 dpi	for press (publication or high-end printing)

Scanning for Enlargement:

If you are planning to enlarge your original graphic, then the resolution setting when scanning has to be increased by the same percentage as the percentage of enlargement.

Example:

To scan a 3x5 original so it can be published for print (150 dpi) at 6x10, you are doubling the size of the image, so you should double the dpi, which in this case would be 300. In order for you to have enough resolution for the publication you would need to scan the original 3x5 at 300 dpi. That would give you enough resolution to enlarge the original to 6x10 and would reduce the final resolution to 150 dpi.