Screen frequency

Measure of the fineness of a printing screen in lines per cm (L/cm) or lines per inch (lpi). Grids are used to reproduce gradients of tonal values in images or coloured areas. For images, the grid should be so fine that the eye perceives colour gradients as flowing. A usual screen frequency in offset printing is 70 L/cm. The image is divided into 70 x 70 horizontal and vertical grid points.

Selecting the screen width

Screen widths must be selected differently depending on the printing process, application and viewing distance. For large format posters, the viewing distance is so large that a screen frequency of 10 L/cm may be sufficient.

Related Terms

See also screen angle.