The basic protective elements in artwork comprise guilloches. They are formed by a system of very fine contiguous lines that are not interrupted. A wide choice of shapes as stripes, frames or rosettes is available. Protective impress are another graphical protective element. Generally they cover majority of the paper or document surface and they may be supplemented with a stylized drawing. They are normally printed by a special printing technique - iris. A gradual transition between two colours is concerned. The type of the 1 dot size is already considered as micro text. This one has a very important protective role, as well.