High-quality images can be obtained from:
High-resolution stock photography
High-quality scanned images
Digital cameras with a high quality of 2.4 mega pixels or more
Remember – DO NOT take any images from the Internet, because most images you will find on the web are protected by copyright laws, and these images are not high resolution
Monitor resolution is much lower than the resolution of printers, so just because an image looks sharp on the screen, doesn’t mean it will print well.
If purchasing an image from a royalty-free website, please make sure that you choose a high-resolution image of 350 dpi.
Your original file needs to be created at a resolution of 350 dpi (150 dpi for signage). If a file is created at a low resolution and manually changed to a higher resolution, it will not change the quality of the image. The only difference it would make is that the file would be rescaled, and the density of the pixels or dots would change, not the number of dots or pixels in the file.
When you take a picture from a digital camera, it must be set at a high resolution in order to result in 350 dpi. We recommend you do this because you cannot change the resolution of a picture after it has been taken. Whenever you change the dimensions of an image or picture, the resolution changes also. The more you reduce the dimensions of a picture, the higher its resolution becomes. For this reason, we ask that you make sure that you save the picture at 350 dpi.
Image resolutions can change if the image is resized or scaled in the page layout application, or if the image is resized or scaled when the file is converted to the PDF format.