Under Color Removal (UCR): Removing excessive densities of cyan, magenta and yellow in neutral shadow areas to allow for more press controllability without plugging up the shadows
Undo: A common software command which cancels the previous action.
Unit: In multicolor printing presses, refers to the combination of inking, plate and impression operations to print a single color. A four color press has four printing units each with its own inking, plate and impression functions.
UNIX: A general-purpose, multi-user, multitasking operating system invented by AT&T. UNIX is powerful and complex, and needs a computer with a large amount of RAM memory to support its power. UNIX allows a computer to handle multiple users and multiple programs simultaneously. And it works on many different computers, which means you can often take applications software and move it _ with little changing _ to a bigger, different computer, or to a smaller, different computer. This process of moving programs to other computers is known as "porting."
Unsharp Mask: A masking method done electronically to exaggerate the edges of the images and the difference between light and dark areas or hues to enhance the detail in the final reproduction. (See also Detail Contrast and Electronic Enhancement.) Also known as peaking.
URL: Uniform Resource Locator. The primary naming scheme used to identify Web resources, URL's dfefine the protocols to be used, the domain name of the Web server where a resource resides, the port address to be used for communication, and the directory path to access a named Web document or resource.
USENET: An Internet protocol and service that provides access to a vast array of named newsgroups, where users congregate to exchange information and materials related to a specific topic.
User Interface: The method by which a user gives instructions to a computer and receives a response.