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December 2017 · No. 4 NEWS Business Unit Sheetfed

PANTONE GUIDE UPDATES

Since the PLUS SERIES New color Guide added Total colors Colors missing from your last guide update was launched back in 2010, three Launch dates in the Guide color collections have been updated. 2010 224 1341 If you haven’t updated in the last 6+ years- you’re missing 756 colors Since 2010, 756 color palettes have 2012 336 1677 If you haven’t updated in the last 5 years- you’re missing 532 colors been added to the guide. 2014 84 1755 If you haven’t updated in the last 3 years- you’re missing 196 colors 2016 112 1867 If you haven’t updated in the last 2 years- you’re missing 112 colors

Color beyond technical constraints Specifications Ink From the color selection to the finished printing product, many • fastness: … • Pigment (origin, criteria can influence the colored result. The process is quite • food packaging grinding, concentration) complex. Each element in the graphic chain will have to combine • varnishing/laminating • Selection of a suitable requirements and technical constraints in order to guarantee the • sterilization ink range, which meets color required on the substrate by the brand owner. Specifications allInk technical requirements Sometimes it can be difficult to reach the target color due to tech- nical constraints (specifications, material, etc.). If the has to match a bright color on an absorbing paper or on recycled paper, it is almost impossible to get the freshness and brightness of the required shade because of the paper’s porosity. Often, there is Substrate confusion between color and aspect. The aspect takes into account Printing Process • intrinsic the gloss, texture, and the nature of the material which we unfortu- Substrate process nately are unable to reproduce through a colored ink. • whiteness • ink film thickness Sometimes, have to develop colors on a greyish • opacity/transparency • mechanical aspects substrate. Furthermore, color formulas have to be light resistant. • porosity/absorption • chemical interaction In the case of a transparent ink, the color of the substrate is • aspect: metalized… • drying conditions revealed through the printed ink layer. If the ink is very clear, the color of the substrate is revealed to a greater extent. The visual result of a printed color depends on a multitude of Additionally, a lightfast pigment is generally duller than a pigment parameters that have to be anticipated as soon as the product is that is non-lightfast. In this case, colorists are faced with three created. All colors and desired aspects are not feasible on press. problems which limit the ability to match the target color. One solution is to use PantoneLive. PantoneLive offers color standards which are more in line with industry since they depend on the print- 1- Transparent and light Ink ing process and ink technology and are based on current and varied material ranges (cf COLOR NEWS No.3). The ink manufacturer is also 2- Substrate greyish an essential contact who can recommend the most suitable ink series and offer the best compromise for the desired application, taking 3- Lightfast pigment use: duller/dirtier into account the specifications, type of substrate, and the inks.

Siegwerk France S.A.S. · F-74105 Annemasse/France · Business Unit Sheetfed – Center of Competence · Tel. +33 450 87 74 00 · www.siegwerk.com COLOR NEWS Business Unit Sheetfed

DO = log (I0 /IR) RECEPTOR Why measure density? I0: Incident Light I : Reflected Light In offset printing shops, density control is essential. By measuring R IR is always less than IO. the densitometry of the full tones, the operator can identify the Thus, the optical density LIGHT IR film thickness variations of the ink applied on the substrate and is always positive. Its value FILTER readjust the quantity of ink accordingly. increases as the surface absorbs light (that is, the Io With the 4-process color system, the densities , , ink layer is thick, or is INK and have to be particularly stable so that the colors , highly pigmented). MATERIAL , and (obtained by superposition of two primary colors) are well balanced. Filters are automatically setup according to the color measurement: Moreover, injects a contrasting effect to the image. Filter Green to measure MAGENTA DO Filter Red to measure CYAN DO Filter Blue to measure YELLOW DO

The two figures are chromatically balanced, but the densities of the Dry and wet ink surfaces reflect light differently. Freshly printed ink fulltone surfaces are different. has a smooth surface like a mirror. As a result, density measure-

Here, the densities are uniform, but ment indicates a higher value. When drying, the surface of the ink the color balance is not respected adopts the irregular structure of the paper. Density measurement because of the dot gain. indicates a lower value compared to wet ink.

Source: System Brunner To remove the surface influence on the results, we recommend To measure the density of a printing, we use densitometer by using the polarization filter for density measurement. Thanks reflection. Density is a function of the amount of reflected light. to this filter, waves can only pass in one single direction. We can also measure density of . In this case, the mea- Typical values values of of densities, densities, conventional conventional inks, inks, full full tone, tone, independent sured reflectance corresponds partly to the light reflected by the ofindependent ISO12647-2 of ISO12647-2certifications certifications dot screen and partly to the light reflected by the substrate. From the densitometry, it is possible to deduce the per- centage of coverage, thanks to the Murray-Davies equation. The result gives the proportion of the total area covered by the dots.

Ex: P. Magenta Colorimetric or applied at several ink densitometric control? layers [0,7;1,5] g/m² Target values Today, in the printing industry, the ink layer or density adjustment ISO2846-1 is closely linked to the colorimetric control of the ink. Colorimetric deviation DE* Magenta turns yellowish Indeed, since the start of PSO standards right up until the last 13.00 when the ink film thick- 10.50 ness increases. The color update (12647-2: 2013), printers rely on the process color L*a*b* 8.00 is moving farther away values to calibrate their press and certify their printing process 5.50 3.00 from standard target (density, dot gain, color superimposition, etc.). 0.7000 0.9000 1.1000 1.3000 1.5000 1.7000 Grammage values.

Based on the kind of substrate, the printer selects the suitable Optical Density In terms of densitometry, colorimetric values from the PSO standard. Once the color deviation 2 saturation is reached (DE) is optimized on the test print, the optical density is measured around 1.10 g/m² and becomes the new target for subsequent jobs. Density and 1 (density value = 1.70) 0.6000 0.8000 1.0000 1.2000 1.4000 1.6000 are both linked to the ink layer. By increasing the ink charge, the densitometric and colorimetric variations are clearly visible. We have discussed how optical density is related not only to the However, beyond a certain inking threshold, the density reaches its ink, but also to the printing conditions like press, substrate class maximum, or saturation. So, the density control cannot substitute (glossy coated, matt coated, uncoated, synthetic, etc.), blankets, the spectral measurement to evaluate the color deviations. printing plate, dampening characteristics, deposit, etc.

Siegwerk France S.A.S. · F-74105 Annemasse/France · Business Unit Sheetfed – Center of Competence · Tel. +33 450 87 74 00 · www.siegwerk.com COLOR NEWS Business Unit Sheetfed

Densitometer & Spectrodensitometer The densitometer is a measuring instrument that is equipped with Heidelberg three filters.* This device captures the reflected light through the ink film to determine the density of the ink, the dot gain, and the Prinect Image Control 3: trapping from the control chart. Unlike the spectrophotometer, Allows the simultaneous control of the full the densitometer doesn’t measure color. printed image and inking correction online in all print groups. The spectrodensitometer is more efficient because it combines densitometric and spectral measurement (colorimetric). Thirty-one points are instantly measured between 400 and 700 nm. Konica Minolta

X-Rite SpectroDensitometer FD-7: Allows color measurement by considering SpectroDensitometer eXact: the fluorescence contained in the paper A touchscreen and portable colorimetric under any illuminant, including D50 (M1). instrument. Ideal for controlling process prints that require a variety of traditional Automatic chart reader FD-9: tools, while retaining the ability to add Only four minutes are required for the more features as needed. FD-9 to measure a chart composed of 1500 patches, from the insertion of the Automatic reading system IntelliTrax2: printed chart to the measured data Analyzes the control range of a typical display. With the FD-9, lots of data* can print sheet in less than ten seconds. be obtained in a single measurement. Measures process colors, spot colors, PANTONE® colors, paper color, tonal value *under multiple measurement conditions increase, gray balance, and ink density. (M1, M0, M2)

Did you know?

Why do lobsters Researchers already knew that the carapace of lobsters is rich in change color astaxanthin. This pigment in the carotenoid family is found in different crustaceans, plankton, certain micro-algae, and fish when cooked? such as , or even in bird feathers. For lobster, it interacts with a protein called crustacyanin to give the blue color that helps On our plate, the lobster has a beautiful orangey red color. the animal hide from its predators. But when cooked, the protein However, before going into the pot, the carapace of the animal is disintegrates because it is not heat-resistant and thereby releases a dark blue, so a color transformation takes place that has been the astaxanthin which, as a result, becomes orange again. puzzling scientists for decades. But now an international team has identified the chemical process behind this transformation. Source: Sciences et Avenir

Siegwerk France S.A.S. · F-74105 Annemasse/France · Business Unit Sheetfed – Center of Competence · Tel. +33 450 87 74 00 · www.siegwerk.com COLOR NEWS Business Unit Sheetfed

The benefits of extended

Gamut: This is a color set which is reproducible with a certain What is extended gamut equipment: , computer screen, printing process, etc. It is represented as an envelope in a 3-axes system. A process of color printing? synthesis cannot reproduce all the colors visible to the human eye. The basic colors used are crucial since the size of the gamut will Printing in expanded or extended gamut means that the depend of them. package is printed by superposition of a CMYK + two or three additional ink combinations (orange/green/blue) in Two areas are represented below. The «process colors» gamut order to replace spot colors. About 50% of PMS colors would (the core) is compared to the extended «process + 2 colors» gamut be achievable in 4 color process. The ink’s addition to the (outer envelope). The scatter plot represents Pantone formulations classical range CMYK enables printers to achieve a larger made in the sheetfed department. By working in hexachromy, the color panel and better quality. envelope is wider. This system makes it possible to cover more PMS shades in the «Orange» and «Green» zones. Multiple equipment is needed for prepress to analyze and decompose the image and to reproduce it in a multichrome Gamut Process Colors + way. Equinox™ is one of the solutions proposed by Esko, Gamut Process Colors Orange + Green which manages the shades conversion to CMYK or to extended gamut. According to the printing process and prerequisites, CMYK printing can replace some or all of the spot colors. The software predicts the gamut’s ability to convert the spot colors accurately, whatever the ink set. With this kind of system, printers don’t have to change spot colors during and after each packaging production. This allows them to increase the productivity of their presses, while reducing ink costs. Gamut Process Colors + Gamut Process Colors However, in offset, it is more difficult to substitute an ink for- Orange + Green mulation by superimposing and juxtaposing points of several primary colors. Just a small variation in the inking (density), dot gain, or trapping will definitely change the color. Due to technical constraints, the matching of spot colors through a multichrome system (halftone) is tricky, especially as the brand owner’s color requirements are very strict.

In UV flexo, the printing process and trapping problems are much less critical thanks to the systematic inks drying inter- group. There is no longer an issue due to emulsion (dot gain), and inking variations are lower. Halftone printing is more Screen shots realized with the 3D viewer tool - IFS6.3 -Xrite. reproducible and feasible because there are fewer machine setting fluctuations. The Colibri® system by Konica Minolta offers an equivalent The feasibility of multichrome jobs is related to the printing «3D gamut viewer» tool for viewing color recipes, ink ranges, and process and also to the level of colorimetric expectations. standards libraries in the 3D CIELAB . It displays the true color envelope and color dots, allowing operators to track the Topic to follow in the next edition of COLOR NEWS color path, to identify and reduce the number of similar products in a range, to spot gaps in the color space, and to visualize which color can be achieved with process inks or with hexachromy.

Siegwerk France S.A.S. · F-74105 Annemasse/France · Business Unit Sheetfed – Center of Competence · Tel. +33 450 87 74 00 · www.siegwerk.com