The Dultgen halftone intaglio process is a photoengraving technique invented by, Arthur Dultgen and is widely used today in commercial colour work.

Two positives are made from the Continuous tone

Continuous tone

A continuous tone image is one where each color at any point in the image is reproduced as a single tone, and not as discrete halftones, such as one single color for monochromatic prints, or a combination of halftones for color prints....

 copy, one through a halftone

Halftone

Halftone is the reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size, in shape or in spacing...

 screen or a special contact screen and the other without a screen.

A sheet of carbon tissue is then exposed first to the screened positive

Negative (photography)

In photography, a negative may refer to three different things, although they are all related.-A negative:Film for 35 mm cameras comes in long narrow strips of chemical-coated plastic or cellulose acetate. As each image is captured by the camera onto the film strip, the film strip advances so that...

, which produces an image of dots of varying sizes, then to the continuous-tone positive, which produces differing degrees of hardening of the dot image. The array of dots vary not only in width but also in depth so as to extend the range of tonal values to be reproduced. This method thus uses two methods for controlling tonal values.