Dobivanje spotne boje pomoću procesnih boja

master's thesis

• Author: Mario Savović
• Mentor: Lidija Mandić (mentor)
• Committee member: Tajana Koren Ivančević (član povjerenstva)
• Committee member: Lidija Mandić (član povjerenstva)
• Committee member: Ante Poljičak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Graphic Arts; Zagreb
• Defense date and country: 2013-9-24, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Graphic Technology

Abstract

Tisak u boji se danas radi najčešće pomoću četiri glavne procesne boje. Spotne boje se dobivaju miješanjem po zadanoj recepturi, te se njima znatno povećava gamut reprodukcije. No takav tisak je dosta skup i ponekad nepotreban, pa se spotne boje konvertiraju u procesne i tako tiskaju.

U ovom radu je pokazano koji su rezultati tiska spotnih boja pomoću procesnih. Otisnuti su uzorci na oba načina, te su napravljene usporedbe pomoću spektrofotometrijskih mjerenja. Određena je razlika među bojama, ΔE, te su prikazani grafikoni CIE Lab vrijednosti za svaki par boja. Na taj način se vidi kod kojih boja je veća razlika, a kod kojih manja.

Rezultati su dali velike vrijednosti ΔE razlike boja, za većinu uzoraka. Kod nekih uzoraka ta vrijednost je manja, i iznosi ΔE = 3,3, odnosno ΔE = 4,2. Ta je razlika vidljiva ljudskim okom, ali za tisak spotne boje pomoću procesnih nije toliko velika. Ostale razlike među bojama su veće od ΔE = 10. Zaključak je da se spotne boje ne mogu otiskivati procesnim bojama, ako su izvan gamuta reprodukcije. Hexachrome tehnika ofsetnog tiska koristi dodatnu narančastu i zelenu boju, pa je i gamut reprodukcije veći. Na taj način se može obuhvatiti i otisnuti znatno veći broj spotnih boja.

Abstract (english)

Colour print today is usually done by using four process colours. Spot colours are made by mixing basic colours using formula guide. Spot colours give much wider reproduction gamut, but using them in print is expensive and sometimes needless, so spot colours are converted to process colours and printed that way.

In this paper it is shown how spot colours look when printed with process colours. Test pieces are printed both ways, and then compared using spectrophotometric measurements. For every colour the difference ΔE is calculated. Also, colours are shown using CIE Lab values for every pair. In that way we can see where are bigger differences and where smaller.

For most test pieces colour differnce ΔE is quite big. For some pairs it is smaller, ΔE = 3,3, and ΔE = 4,2. That difference can be seen with human eye, but it is not so big for printing spot colours with process colours. The difference between other pairs is above ΔE = 10. To conclude, spot colour cannot be printed using process colours, if they are out of reproduction gamut. In Hexachrome offset print, where orange and green colour is added, the gamut is much wider, and more spot colours can be printed.

• Keywords: spotne boje; konverzija boja; gamut reprodukcije
• Keywords (english): spot colour; process colours; reproduction gamut
• Language: croatian
• URN:NBN: urn:nbn:hr:216:412185
• Study programme: Title: Graphic technology; specializations in: Graphic technology, Design of graphic products; Course: Graphic technology; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra inženjer/inženjerka grafičke tehnologije (sveučilišni/a magistar/magistra inženjer/inženjerka grafičke tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2024-04-18 19:06:04