Mogućnost realizacijezlatnih tonova sa elektrofotografskim praškastim tonerima

Possibility of realization of gold tones with electrophotographic powder toners

Igor Majnarić¹, Petra Zeljković¹, Dean Valdec²

1 Sveučilište u Zagrebu Grafički fakultet
2 Sveučilište Sjever, Odjel za medijski dizajn

Sažetak

Tehnologije digitalnog tiska sve su zastupljenije u grafičkoj industriji. U elektrofotogrfiji su se nekada koristile samo CMYK i BW tiskarski strojevi, dok je danas moguće realizirati i specijalne boje (bijela, zlatna, srebrna, fluorescentni CMY i lak). Otisci nastali sa zlatnim elektrofotografskim tonerom tako izgledaju vizualno uočljiviji što se može zahvaliti izraženim metalnim sjajem (reflektancijom). U ovom radu istražena je mogućnost realizacije metalnih nijansi (PANTONE) otisnuti u pokrivenosti s 10%, 20%, 40%, 70%, 100% RTV-a koristeći novu generaciju EA praškastim tonerom za tiskarski stroj Xerox Versant 180 Press. Pritom je dodatno ispitan utjecaj rastriranja odnosno dva tipa tipa okruglog rastera (AM raster i FM raster). Za provjeru uporabne mogućnosti ostvarenih metalik efekta (zlatni tonovi) isti motiv otisnut je sa dvobojnim tiskarskim strojem Heidelberg GTO 52 uz korištenje tiskarske boje Alchemy PANTONE 877C proizvođača Huber. Za ispitivanje korištena je standardna papirna tiskarska podloga (Maxi Gloss 170 g/m2). Na svim ostvarenim otiscima izvršena je kolormetrijska usporedba elektrofotografija-ofsetni tisak uz određivanje CIEL*a*b* kolorimetrijske vrijednosti (x-rite Exact) te izračun kolorimetrijske razlike u obojenje ΔE 2000, ΔL, ΔC (Oragin 8.5).
Ključne riječi: Zlatna boja, elektrofotografija, ofsetni tisak, CIE LAB ΔE

Abstract

Digital printing technologies are increasingly present in the printing industry. In the past decade, the electrophotography printing process only used CMYK and BW printing machines, while today it is possible to realize special additional colors (white, gold, silver, fluorescent CMY, and clear). The prints created with gold electrophotographic toner look more visually noticeable, which can be attributed to the pronounced metallic gloss (reflection). In this paper, the possibility of realizing metallic shades (GOLD) printed in coverage with 10%, 20%, 40%, 70%, 100% of RTV was investigated, using a new generation of EA powder toner for the Xerox Versant 180 Press printing machine. The influence of two types of round print element types (AM frequency and FM frequency screening) was additionally examined. To check the usability of the achieved metallic effects (golden tones), the same motive was printed with a two-color printing machine Heidelberg GTO 52 with the use of printing ink Alchemy PANTONE 877C by Huber producer. A standard paper printing paper (Maxi Gloss 170 g / m2) was used for testing. Colorimetric comparison of electrophotography-offset printing was performed on all realized prints with the determination of CIEL*a*b* colorimetric value (x-rite Exact) and calculation of the colorimetric difference in color ΔE2000, ΔL, ΔC (Origin 8.5).
Key words: Gold ink, electrophotography, lithography offset printing, CIE LAB ΔE2000

igor.majnaric@grf.unizg.hr