Rotogravure
Rotogravure printing has its origins in the artistic copperplate printing and engraving. Contrary to the letterpress the rotogravure is characterized by a print form in which the printing elements are deeper than the non-printing images.
Rotagravure for printing on paper and corrugated/packaging has been used for 70 years. A standardized and exact metering ink transfer in rotogravure printing gives high precision pixel repro and best quality in repro of photo/pictures. Also brillant tonal value and fine vignettes honour rotogravure which will subsist in combination of continous-tone illustrations, engraving and flat motives on relatively less printing units.
Rotogravure is the simplest
printing method. It results in the highest, most consistent printing
quality - also on repeat jobs. Rotogravure guarantees fast printing
speeds with excellent and steady results; further the method is cheap
especially on high volumes.
Rotogravure serves market segments
which can not be covered through other printing methods. Besides packaging
rotogravure profits from developments in illustration rotogravure. Although
litho/offset and in the meantime also flexo will show good printing
results and partly also high quality, rotogravure quality is a step
ahead.
Characteristic advantages of
rotogravure are:
- Ideal possibilities in reproduction of photographic motives
- Optimal reproducibility at a longlasting life of the printform cylinder
The most important rotogravure
printing is photogravure, mainly for illustrations with high
editions. The printing form is a steel cylinder copper- or chrome-plated.
Within the printing process the complete surface of the printing form
or the non-printing im-age areas. The ink in the cells will be transfered
on to the print carrier. The image transfer will be effected by electromechanical
engraving or by etching. As a result of digitalized engraving datas
as a diamond burin creates the printing elements on the cylinder which
will then be chromed electrolytically.
Nowadays, another rotogravure method is used for exceptional prints. This method is called die-stamping and in action for:
- Document papers
- Representative business-
and private printed matters
- Security papers, banknotes
and stamps.
Manufactured steel plates or steel cylinders for rotogravure are coated with a photosensitive and simultaneous acide-resistent photoresist (Rockyphot). - After exposing with negative films follows the development with solvents. Then developed steel plates or steel cylinders will be etched in Ferric-III-chloride.
