A 'screen' is a series of ink 'dots', printed on to a paper which gives the appearance of a solid colour. The depth of screen colour can be deepened by increasing the dot frequency (see DPI), or the converse. A graduated screen is one where the DPI is varied across the screen so that you get a fading/deepening effect across the printing.
Found on
http://www.encyclo.co.uk/local/21179
An area of image where halftone dots range continuously from one density to another.
Found on
https://www.encyclo.co.uk/local/22539
No exact match found.
