The information about the size (typically the diameter) of the minimum isolated dot refers to the characteristics of the plate and it is normally completed with the term positive and/or negative.
- Minimum positive isolated dot: 100 µm
- Minimum negative isolated dot: 50 µm
The minimum isolated dot size indicates what is the ability of the plate system to reproduce a self sustaining single printing dot without the presence of surrounding dots that help sustaining with their shoulders. Where by plate system of course we mean the combined result of the characteristics of plate material, imaging and platemaking.
Typically the lower the value of the minimum dot, the better is the quality of the plate.