Pixelated or Low Resolution Images
Images are used that are too low resolution to support a quality print. Can also happen when saving the file from the native program causes the images to be replaced with low resolution versions due to incorrect program settings.
For pieces running in a small colour press (for Island Blue, that is anything under 14" x 20"), the recommended resolution for the quality reproduction of an image is 300dpi at the full size it will be printed.
This image is very low resolution and the text has also been affected. This is an extreme example of a low quality image, but if you can see the pixels (or blocky edges) when viewing the artwork, the image is not suitable for printing. Web images are not recommended for this reason.
Resolution problems are most apparent visually when zooming into the artwork and checking for edge clarity. Graphic programs will allow you to check image quality more specifically.
Artwork at full resolution, including text.
As a visual aid, the red box is the 'safe zone' inside the card where all non-bleed text or graphics need to be placed. As a visual aid, the blue box is the edge of the finished piece or the final size. This is often called the 'trim line'.