An investigation into the enhancement of fingermarks in blood on paper with genipin and lawsone

The abilities of two natural products, genipin and lawsone, to enhance blood contaminated fingermarks on papers of various porosities and colour were investigated and compared to the routinely used amino acid reagents, ninhydrin and 1,8-diazafluoren-9-one (DFO).Fingermarks in blood were deposited as a split depletion series on various paper types and colours for ageing periods of 6 weeks, 4 weeks, 2 weeks and 1 week before enhancement. The developed marks were observed under different lighting conditions, recorded and graded by way of attributing quantitative data to each series.Results indicated that while genipin showed some potential as a reagent for the enhancement of latent fingermarks, it displayed no suitability for the enhancement of fingermarks in blood on paper. Lawsone also failed to successfully enhance either type of fingermark. Upon comparison of the results with those of ninhydrin and DFO it was found that ninhydrin displayed the highest success rate of development of these marks

Determining the optical stability of printed laboratory substrates with wheat pulp after ageing treatment

The use of recovered paper in the paper and board industry worldwide has increased in the last decade. The recycling process affects several properties of the paper, so recovered pulp needs to be enriched with a certain amount of virgin fibre to increase the strength and quality of the paper, and thus the quality of the print. Since the cellulose-based printing substrates are sensitive to photolytic damage caused by exposure to light and high temperature, the focus of the research was to evaluate the stability of digital UV inkjet prints on laboratory substrates with wheat pulp. Assessment of the optical stability of laboratory substrates and prints made on them after ageing treatment was based on the reflectance spectra measurements before and after artificial ageing. In order to observe the optical changes that occur in cellulose printing substrates, unprinted and digital printed substrates were placed in an artificial ageing equipment SunTEST XLS+ test chamber according to standard ASTM D 6789-02. The test chamber emits visible and near ultraviolet electromagnetic radiation in the range from 290 nm to 800 nm. With the deterioration of the optical stability of unprinted and digital printed substrates, it was observed through the reflectance spectra (R) and the Euclidean colour difference (ΔE00*) that the highest colour degradation of all analyzed samples, occurs in the first 48 hours of artificial ageing. The results of this analysis confirm that the addition of wheat pulp in paper pulp provides better optical stability of unprinted and digital printed laboratory substrates

Light permanence wrap prints produced with CMYK UV inkjet inks

Nowadays, Inkjet technology has become one of the most widespread printing technologies in car industry (car wrapping = printing and wrapping the whole vehicle or a part of a vehicle in printed foil). Printed wrap foils are, after the wrapping process, exposed to the same conditions as a lacquered vehicle: intensive sunlight, high and low temperatures, rainfall, snow, ice, particles or bugs that the vehicle encounters while driving, etc. In this paper we tested different types of wrapping foils (Orajet, 3M Scotchcal and 3M Controltac) and solvent inkjet inks to investigate the influence of different types of wrap foils on the real reproduction of UV ink jet coloured imprints, as well as their stability fluctuations during ageing. The inkjet prints age faster under the influence of UV light (Xenon lamp in SolarBox) in a period of 240 hours. The results show that the 3M Scotchcal foil has the best CMYK stability

Effect of Five Essential Oils as Green Disinfectants on Selected Photographic Prints: Experimental Study

Albumen, silver gelatin and chromogenic prints are found abundantly among photographic collections in Egypt. Due to the uncontrolled environment in archives and libraries, this precious visual heritage with its high protein and cellulose content provides the right culture medium required for fungal growth. Many essential oils have been proven to have antibacterial and antifungal properties. Essential oils offer a safe alternative to other common disinfection methods; however, their effect on the properties of photographs have not received much study. This paper studies the effect of vapors of anise, cinnamon, clove, lavender and thyme oils on albumen, silver gelatin and chromogenic prints, to find a proper disinfection method that is user-friendly and environmentally safe and respects the nature of photographic materials. Essential oils were provided by the National Research Center (NRC) in Cairo, Egypt. Artificially aged albumen prints, and naturally aged silver gelatin and chromogenic prints were exposed in desiccators to the selected essential oils in the vapor phase for a period of 5 days. All samples were artificially aged at a temperature of 80°C and 65% RH for a period of 5 days to study the long-term effects of the tested treatments. Treatments were evaluated using several techniques including visual inspection, microscopic inspection, colorimetric measurements, and attenuated total reflectance Fourier transform infrared spectroscopy. Results showed that all tested essential oils had a very slight effect on the tested photographic samples; however lavender oil was found to be the best option, specifically in terms of preserving the chemical properties of the photographic surfaces.Albumine, gelatine d'argento e stampe cromogeniche si trovano in abbondanza nelle collezioni fotografiche in Egitto. A causa dell'ambiente non controllato negli archivi e nelle biblioteche, questo prezioso patrimonio visivo con il suo alto contenuto di proteine ​​e cellulosa fornisce il terreno di coltura per la crescita dei funghi. Molti oli essenziali hanno dimostrato di avere proprietà antibatteriche e antimicotiche. Gli oli essenziali offrono un'alternativa sicura ad altri metodi di disinfezione comuni; tuttavia, non ci sono molti studi sul loro effetto sulle proprietà delle fotografie. Questo articolo descrive l'effetto dei vapori di oli di anice, cannella, chiodi di garofano, lavanda e timo su albumine, gelatina d'argento e stampe cromogeniche, per trovare un metodo di disinfezione adeguato che sia facile da usare e sicuro per l'ambiente nel rispetto dei materiali fotografici. Gli oli essenziali sono stati forniti dal National Research Center (NRC) deI Cairo, in Egitto. Stampe all'albume invecchiate artificialmente, gelatine d'argento invecchiate naturalmente e stampe cromogeniche sono state esposte in essiccatori agli oli essenziali selezionati in fase vapore per un periodo di 5 giorni. Tutti i campioni sono stati invecchiati artificialmente a una temperatura di 80 °C e 65% di umidità relativa per un periodo di 5 giorni per studiare gli effetti a lungo termine dei trattamenti testati. I trattamenti sono stati valutati utilizzando diverse tecniche, tra le quali ispezione visiva, ispezione microscopica, misurazioni colorimetriche e spettroscopia a infrarossi in trasformata di Fourier a riflettanza totale attenuata. I risultati hanno mostrato che tutti gli oli essenziali testati hanno avuto un lieve effetto sui campioni fotografici testati; l'olio di lavanda è risultato essere l'opzione migliore, in particolare, in termini di salvaguardia delle proprietà chimiche delle superfici fotografiche

Optical deterioration of samples printed with basic Pantone inks

This study focuses on the research of changes in the optical characteristics of selected offset inks (Yellow, Red 032, Process Blue and Black) printed as a part of Pantone colour book. These changes that occur as a result of natural and accelerated ageing (caused by thermal and UV/VIS radiation) were observed through reflectance spectra in the visible region. A Pantone colour book is a system for identifying, matching and controlling ink colours in the graphic industry. This colour book is the international reference for accurate colour communication. The durability of colours and its unchanged quality play an important role in ensuring accurate colour communication and control. In order to examine optical modifications, the samples were exposed to elevated temperatures and UV/VIS lamp radiation. The FTIR spectroscopy was additionally used for the characterization of printed inks before and after ageing

Effects of Non-Wood Fibres in Printed Paper Substrate on Barrier and Migration Properties

Nowadays, there is a strong initiative to use recycled or biodegradable materials in all aspects of production including the graphic industry. In this study, paper was used as a material fulfilling the two of mentioned properties. Under laboratory conditions, papers were made of 70% pulp from recycled wood fibres with an addition of 30% straw pulp (wheat, barley or triticale). Considering the importance of the possibility of printing such media based on their end use, the influence of fibre type on vapour barrier properties was studied and overall migration to hydrophilic and fatty food simulants was measured. Analyses were performed on digital, flexographic, and offset prints obtained by printing laboratory papers with UV-curable black ink. It was found that prints produced using the offset technique, in which the ink remains on the surface of the paper, had lower overall levels of migration compared to other printing techniques. The paper produced appears to have the potential to be used as a secondary food packaging material

Stability of wide format ink jet prints for outdoor application

U ovom radu se prikazuju rezultati istraživanja otpornosti na vremenske uvjete inkjet otisaka velikog formata dobivenih piezo-električnom tehnologijom s bojilima na osnovi pigmenata i UV sušećim bojilima. Uzorci su izlagani stvarnim vanjskim uvjetima. Prikazuju se promjene optičkih karakteristika podloge kao i razlika obojenja te volumen gamuta otisaka u odnosu na globalno i difuzno zračenje, temperaturu i vlagu zraka. Rezultati pokazuju da ΔE* za žuto i crno bojilo na otisku s UV sušećim bojilom eksponiranom ljeti, je manje u periodu kada se utvrđuje povećanje volumena gamuta tijekom izlaganja, između ostalog i radi većeg globalnog zračenja. Volumen gamuta otiska s UV sušećim bojilima se povećava tijekom zimskog izlaganja, kao i do određenog vremenskog intervala u ljetnom izlaganju, da bi se nakon toga s daljnjim izlaganjem smanjivao. Međutim, volumen gamuta otisaka s bojilima na osnovi pigmenta smanjuje se tijekom izlaganja, a ΔV za ljetno izlaganje je 37 % veće u odnosu na zimsko.In this paper the research results of the weather resistance of the Ink Jet wide format prints obtained by piezoelectric technology with pigment-based and UV curable inks are presented. The samples were exposed to the real outdoor conditions. Changes in the optical characteristics of the substrate as colour difference and gamut volume of prints in relations to the global and diffusion radiation, air temperature and humidity are presented. The results show that ΔE* for yellow and slightly less for the black on prints with UV curable inks exposed in summer is less in the period when gamut volume increases with time of exposure due to global radiation increase. Gamut volume of prints with UV curable inks increases during winter, as well as in the specific time interval in summer to subsequently reducing with further exposing. However, the gamut volume of prints with pigment-based ink is reduced during exposing, and ΔV for daylight exposing is 37 % higher compared to winter

Lightfastness of Water-based Inks vs. Latex Water-based Inks

This study focused on the lightfastness properties of non-latex water-based inkjet inks and latex inkjet inks for conventional process colors, i.e., cyan, magenta, yellow, and black. Lightfastness is defined as the property of ink that describes the degree of resistance to fading when exposed to light. Lightfastness varies among inks based on their formulation. The degradation of inks caused by light happens when the light is absorbed by the pigments and reacts with the pigments and molecules in the printed substrate. This research evaluated the lightfastness degree of water-based inkjet inks vs. latex inkjet inks. The experiment used printed samples subjected to equal amounts of light, using established methodologies for accelerated aging. The data gathered from the prints included information on color shift as expressed by L*a*b* and ∆E00. Data analysis was performed to compare the before and after exposures of the two types of ink. It was concluded that the latex inkjet ink formulation improved the lightfastness properties when compared to water-based inkjet inks, particularly with magenta and cyan

Improving the security of conventional and UV luminescent flexographic prints by modification of the printing inks using nanoparticles

The security and protection of printed products against counterfeiting have become more advanced and increasingly used in the field of graphics technology. In this research, conventional process black (PB) and UV luminescent (UVL) inks used in flexography, modified by nanoscale silicon dioxide (SiO2), anatase and rutile titanium dioxide (TiO2), and zinc oxide (ZnO) at different concentrations were used. The purpose of adding nanoparticles to these inks was to protect PB and observed UVL inks from counterfeiting without significantly affecting the optical appearance and colourimetric properties of the printed motives. The results have shown that nanoparticles did not significantly affect the spectral reflectance of UVL inks observed under UV irradiation or the visual effect of UV luminescence. In addition, the nanoparticles had a negligible effect on the optical and colourimetric properties of PB inks, as evidenced by a slight increase in colour lightness after the addition of nanoparticles. Indirect detection of nanoparticles through their interaction with PB and UVL inks was possible through FTIR-ATR spectroscopy, which showed changes in the spectra of PB and UVL inks with nanoparticles compared to nanoparticle-free inks in the fingerprint region. This research opened the possibility of expanding the use of nanoparticles of different types and concentrations for process, spot, luminescent and other special and conventional inks in the field of graphic technology

Improving the security of conventional and UV luminescent flexographic prints by modification of the printing inks using nanoparticles

The security and protection of printed products against counterfeiting have become more advanced and increasingly used in the field of graphics technology. In this research, conventional process black (PB) and UV luminescent (UVL) inks used in flexography, modified by nanoscale silicon dioxide (SiO2), anatase and rutile titanium dioxide (TiO2), and zinc oxide (ZnO) at different concentrations were used. The purpose of adding nanoparticles to these inks was to protect PB and observed UVL inks from counterfeiting without significantly affecting the optical appearance and colourimetric properties of the printed motives. The results have shown that nanoparticles did not significantly affect the spectral reflectance of UVL inks observed under UV irradiation or the visual effect of UV luminescence. In addition, the nanoparticles had a negligible effect on the optical and colourimetric properties of PB inks, as evidenced by a slight increase in colour lightness after the addition of nanoparticles. Indirect detection of nanoparticles through their interaction with PB and UVL inks was possible through FTIR-ATR spectroscopy, which showed changes in the spectra of PB and UVL inks with nanoparticles compared to nanoparticle-free inks in the fingerprint region. This research opened the possibility of expanding the use of nanoparticles of different types and concentrations for process, spot, luminescent and other special and conventional inks in the field of graphic technology