Limited editing is available in this mode. Grayscale images made up of 8 bits of information per pixel and use 256 shades of gray to simulate gradations in color. RGB images use three colors to reproduce up to 16.7 million colors on-screen. Duotone mode used for monotones, duotones, tritones, and quadtones. These images are grayscale, single-channel images with 8 bits per pixel.
CMYK images consist of the four colors used to print color separations.
Multichannel images have 8 bits per pixel, and are used for specialized printing purposes. Lab images use three components to represent color. An image with a high resolution contains more, and therefore smaller, pixels than an image of the same printed dimensions with a low resolution. However, increasing the resolution of an image scanned or created at a lower resolution only spreads the original pixel information across a greater number of pixels and rarely improves image quality. To determine the image resolution to use, consider the medium of final distribution for the image.