Resolution & Size of Images for Printing

The size (and detail) of a screen image is determined only by the pixel dimensions of the image and is not affected by the image resolution. Image resolution affects only the size and detail (or quality) of a hard-copy printed image. Increasing image resolution improves the detail (or quality) of a printed image but with a proportional reduction in image size. The size of a printed image is determined by dividing the pixel dimensions of a screen image by the image resolution: e.g., with a screen image of 800 x 600 pixels and image resolution set to 200 dots per inch (dpi), a printed image would be 800/200 = 4 inches x 600/200 = 3 inches. As a guide, the following table gives the dimensions of printed images at different resolution settings for a screen image of 800 x 600 pixels:

Image files at KBS BioShots have a default resolution setting of 72 dpi. The best method of re-sizing an image for hard-copy printing is by first re-setting the resolution to the highest value that gives the approximate print dimensions required (e.g., by using the table above as a rough guide) and then cropping this higher resolution image to the exact size required for printing. This can be done in most image-editing software and will produce a more detailed and better quality print than simply re-sizing and printing a screen image left at the default resolution. A resolution of 200-300 dpi should be used for 'photo-quality' printing.