Sublima Screening

 

Sublima combines two proven screening techniques – traditional Amplitude-Modulation “AM” and Frequency-Modulation “FM” screening. This combination of both screening techniques produces a finished product that combines the detail of “FM” (stochastic) screening while still being able to achieve the flat tints characteristic to traditional “AM” (conventional) screening. How does it do this? The secret is in the fact that it prints using a traditional 240 line-screen until it reaches it’s highlights...where normally the dots would be too small for a press to be able to print is where Sublima steps in. Sublima makes dots no smaller than the press will print...instead it makes the screen a random pattern similar to “FM” (Stochastic) screening, yet maintaining these dots along the conventional screen angles.

Conventional Amplitude Modulation (AM) screening places halftone dots in a consistent pattern, with the size of individual dots varying to simulate the tone values of the original. The size of the halftone dots can vary from 10 to 200 microns, although coarser newspaper screens may produce dots up to 350 microns. This type of screening produces good quality “flat tints”, however lacks the fine detail that can be produced by “FM” screening, while usually leaving a visible “rosette”.

Frequency Modulation (FM) Screening, which is sometimes referred to as stochastic or random-screening, has the same goal as AM screening-artifact-free reproduction. It uses smaller microdots that reproduce tone values by adjusting the number of dots in a given area. Stochastic screening typically breaks up the image tone into smaller fragments of equally-sized dots and randomly positions them over the same surface area. These microdots are smaller than traditional halftone dots, typically in the 20 to 35 micron range. This type of screen produces sharp detail, however it usually produces graininess in flat tint areas and is less responsive on press than “AM” screening in making slight color moves.

Once Sublima reaches the smallest and easiest printable dot for our press, it makes the dots no smaller. Instead, it uses a patented method to remove dots. Even though the dots at the highlights may appear to be random - you will notice the dots align along the existing angles.