|
|
A study on the Lightfastness of Color Prints
Štěpánková, Eva ; Reháková, Milena (referee) ; Dzik, Petr (advisor)
This paper gives a brief overview on the published and accepted standards and methods for colour photography and print lightfastness measuring and evaluating. A comparison of selected valid standards and evaluation suggestions has been made. Sample sets was produced by various photographic processes and printing techniques. Identical sample sets were used in both long-term and accelerated ageing experiment. In this thesis, the degradation speed is expressed as a formal rate constant, which was calculated from the dependence of normalized gamut volume on the exposure dose. Photographs and prints were compared on calculated lifetime basis. A failure of reciprocity law was observed, which indicates a lower credibility of estimated lifetime predictions based on accelerated ageing.
|
|
|
Lightfastness of inkjet prints
Buteková, Silvia ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
The stability of inkjet print is influenced by a lot of factors. Just the surrounding environment in image stability plays an important role. When the prints fade, not only this does occur by light exposure, but also considerable effect has relative humidity, ozone and other air pollutants. The types of receiving layers or ink composition belong to other factors, which affect the stability of prints. This diploma thesis deals with the long-term ageing of digital prints produced by ink jet technology. The study of resistance of inkjet prints was realized on nine different types of media. Samples were prepared with use of dye-based and pigment-based inks. The attention was especially focused on the influence of light on print durability, but study was also oriented on the impact of ozone. The samples were exposed to the indoor daylight. Changes in printed colours were measured and evaluated in colorimetric quantities. In this study of inkjet prints degradation the dependence of colour gamut volumes on UV and VIS exposure dose was evaluated.
|
|
|
Accelerated testing of lightfastness of indoor furniture coatings
Kulhánková, Michaela ; Drábková, Klára (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with the study of the current methods of testing and evaluation of lightfastness of interior paints. Their fading is caused mainly by the influence of solar radiation. The first part provides the basic information needed to understand the experiment. In the second part, wood samples with various white varnishes and coatings were subjected to accelerated testing of lightfastness. The experiment was performed by exposing these samples to xenon lamp through the window glass filter in the solar chamber. Changes in the color of the samples were evaluated based on the measurement of the reflection spectra from which the colorimetric quantities were calculated and then displayed in the color space CIE 1976 L*a*b*. The conclusion was focused on the final real life of the samples, their mutual comparison and evaluation of the most suitable materials.
|
|
|
Barrier Polymeric Layers for Inkjet Prints Protection
Štěpánková, Eva ; Čeppan, Michal (referee) ; Ďurovič, Michal (referee) ; Veselý, Michal (advisor)
Práce podává přehled o dostupných a využívaných metodách, normách pro testování a hodnocení světlostálosti barevných fotografií a tisků. Bylo provedeno porovnání jednotlivých platných norem a návrhů na hodnocení. Tato práce pojednává o ochraně inkjetových tisků pomocí lakování. Byl připraven lak kompatibilní s fotografickými médii. Připravená kompozice byla obohacena o UV absorbéry EVERSORB ve dvou koncentracích. Pro srovnání byly také testovány tři druhy komerčních ochranných fotografických laků. Výtisky se třemi barvivovými inkousty opatřené lakovou vrstvou, byly vystaveny jak urychlenému světelnému stárnutí v xenonové testovací komoře, tak urychlenému stárnutí v ozonové testovací komoře. Na základě měřených odrazových spekter byl vypočítaný objem barvového gamutu pomocí softwaru Volga. Byl sledován úbytek gamutů v průběhu světelného stárnutí i při expozici ozonem. Stárnutí vzorků probíhalo do ukončení testu, nebo do dosažení kritéria 30% úbytku objemu barvového gamutu. Také bylo pozorováno selhání recipročního zákona, které ukazuje na jistou nepřesnost při předpovědi dlouhé životnosti vzorků. Pomocí změny barvového gamutu byla posuzována ochrana připraveného laku před UV záření a ozonem. Studované vrstvy laků byly dále charakterizovány na prostupnost kyslíku a vodní páry.
|
|
|
Catalytic fading of inkjet prints
Brablc, Tomáš ; Havlínová,, Bohuslava (referee) ; Veselý, Michal (advisor)
This thesis deals with the principles of inkjet printing, ink composition, receiving layers and print fading. The fading usually does not take place only for one reason, it is affected by more factors at a time. The catalytic fading due to light is studied. The catalytic fading takes place in overprinted areas where are situated more then one ink. The experiment was realized by the exposure of overprinted fields in accelerated ageing test. Mutual influence of two dyes from CMY together and then influence of black dye (K) on these overprinted fields were observed.
|
|
|
Methods of Color Prints Lightfastness Evaluation
Komárková, Hana ; Havlínová,, Bohuslava (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with recent methods of lightfastness evaluation of the colour photographs. It summarizes the experimental methods used for both classic and digitally printed materials. Samples made by using the dye diffusion thermal transfer were put to accelerated and long-term lightfastness tests. Colour changes of the samples were evaluated on the basis of measured reflective spectra from which colorimetric quantities were calculated. The velocity constant of photograph fading was specified by dependence on the loss of normalized gamut volume on the exposure.
|
|
|
Lightfastness of digital color prints
Kulhánková, Michaela ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
In this diploma thesis the current methods of color fastness evaluation of color digital prints were solved. The theoretical part provides basic information needed to understand the experiment. Samples of inkjet prints were subjected to accelerated and long-term lightfastness test. The long-term test took place in the spaces of the Faculty of Chemistry, Brno University of Technology, which fulfilled the condition of direct light in a closed room. For one year, samples were exposed and their reflection spectra were measured at monthly intervals. An accelerated lightfastness test was performed in a solar chamber with a xenon lamp. Only some samples were selected for this test because of the small space in the chambre and thw failure of the instrument. At regular intervals were measured again their reflection spectra from which the colorimetric values were calculated. After completion of the testing, the rate parameter was determined from the dependence of the loss of the normalized gamut volume on different doses of irradiation. In the case of long-term testing, it was based on data from the Hydrometeorological Institute, which gave values of direct outdoor solar radiation. In the accelerated test, the irradiation dose of the sample up to 800 nm was determined. Finally, the lightfastness of each sample was examined and compared with each other and the relevance of the accelerated test was assessed.
|
|
|
Enhancement of print lightfastness by varnishing and lamination
Komárková, Hana ; Reháková, Milena (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with recent methods of lightfastness evaluation of both classic and digitally printed photographs. It summarizes the experimental methods used for colour change measurements. Primarily, it studies an influence of additional protection on lightfastness enhancement. Lightfastness testing of colour prints was carried out by accelerated ageing. Samples were prepared by 3 types of inkjet printers and 3 different print media. The surface of photographs was left untreated or modified by varnishing or lamination. A set of samples, thus achieved, was used to monitor a print behaviour during the light exposure. In conclusion effects of used receiving layer, ink or additional surface treatment were discussed. Colour changes were evaluated on the basis of measured reflectance spectra from which colorimetric quantities were calculated. Results were processed using VolGa application. An actual print-life was calculated from the plot of the normalized gamut volume loss and the exposure.
|
|
|
Accelerated ageing of ink-jet printouts
Buteková, Silvia ; Reháková,, Milena (referee) ; Veselý, Michal (advisor)
Ink jet printing displaces in consequence its versatility the forefront in the printing applications. The prints must be stable for archiving, even if they are exposed to the environment. Now, the improvement of photo stability of ink jet prints is an important goal. This bachelor thesis deals with the ageing of prints produced by ink jet technology. The attention was paid to the influence of light on durability of prints especially. The experiment was made under natural conditions (ageing owing to sunlight). The changes of printed colours were evaluated after some chosen colorimetric quantities were measured.
|
|
|
Lightfastness of digital color prints
Kulhánková, Michaela ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
In this diploma thesis the current methods of color fastness evaluation of color digital prints were solved. The theoretical part provides basic information needed to understand the experiment. Samples of inkjet prints were subjected to accelerated and long-term lightfastness test. The long-term test took place in the spaces of the Faculty of Chemistry, Brno University of Technology, which fulfilled the condition of direct light in a closed room. For one year, samples were exposed and their reflection spectra were measured at monthly intervals. An accelerated lightfastness test was performed in a solar chamber with a xenon lamp. Only some samples were selected for this test because of the small space in the chambre and thw failure of the instrument. At regular intervals were measured again their reflection spectra from which the colorimetric values were calculated. After completion of the testing, the rate parameter was determined from the dependence of the loss of the normalized gamut volume on different doses of irradiation. In the case of long-term testing, it was based on data from the Hydrometeorological Institute, which gave values of direct outdoor solar radiation. In the accelerated test, the irradiation dose of the sample up to 800 nm was determined. Finally, the lightfastness of each sample was examined and compared with each other and the relevance of the accelerated test was assessed.
|
guest ::
