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Each output machine reproduces the same artwork in a different way. However, in the absence of any Color Management the desired result can only be achieved by trial exposures.
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However, with the changing times, the printing houses can now take the help of a spectrophotometers. A spectrophotometer is a photometer (a device for measuring light intensity) that can measure intensity as a function of the color, or more specifically, the wavelength of light. Important features of spectrophotometers are spectral bandwidth and linear range of absorption measurement. The spectrophotometers are widely used in many industries including printing. |
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In printing industry, the device is meant for automatic measurement of most different materials in Large Format, Flatbed, UV and Industrial Printing. The Spectrophotometer Spectro LFP Series 2 is an automatic measuring instrument for both transmission and reflection media to create ICC profiles (International Color Consortium) and is used in modern Color Management for digital output of images.
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With this device, it is possible to create to ICC profiles for digital output equipment for most different materials (both reflective and transparent), single measurements of logo-colors (Pantone) with subsequent check of the color-true printing. Interestingly, printers can also use this as a densitometer to determine density values for films and papers |
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The following materials printed on large format inkjet-printers can be measured automatically: papers, vinyl, textiles, cardboards, plastic plates, gypsum plates, wood, glass, stone, ceramics plates; measure heavy and thick materials (up to 20mm); measure spectral and density values. |
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One company that manufactures such devices is the Italy based BARBIERI electronic snc. The company, a leading player in the wide-format digital imaging and screen printing industry, has recently launched ‘Spectro LFP Basic‘, an entry-level model and the best in class color measuring device. The Spectro LFP Basic was first demonstrated at FESPA Digital in Amsterdam (12. – 14. May 2009). |
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It is targeted to large format printing labs or industrial printers which actually do not have the necessity for transmissive readings but need the special features of a high quality color measuring device especially designed for their needs. Also for textile printers the Spectro LFP Basic is the ideal solution. |
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The new device belongs to the best in class Spectro LFP family and grants the same high measuring quality as the Spectro LFP RT, as stated in the company’s release. It performs fully automatically measurements of any kind of reflective media with a thickness up to 20mm. Due to its big measuring aperture (6mm), it guarantees highest accuracy readings also on difficult media such as textiles, fabrics, banner, mesh, cardboard and ceramics. It is also supported by most Rip software.
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According to the company the Spectro LFP Basic differs from Spectro LFP RT as the measuring aperture is fixed at 6mm, it effects reflective measurements only and it comes at a very interesting price, says the company’s release. The company claims that the Spectro LFP Basic can be upgraded easily to a Spectro LFP RT with all his unique special features such as transmissive readings and switchable measuring aperture. |
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BARBIERI electronic, founded in 1983 by Siegfried Barbieri, made its market launch of the first densitometer (Densy 301). Ever since the introduction of the Spectro LFP in 2004 , the device became the reference spectrophotometer for large format, flatbed and industrial printing. BARBIERI’s special color measuring devices Spectro Swing and Spectro LFP are designed according to the specific needs of the wide-format digital imaging. |
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BARBIERI offers complete and professional packages which for example consist of: Fully automatic reflection and transmission spectrophotometer measuring color charts extremely quickly and with hitherto unknown precision and repeatability; and professional software package for creating ICC profiles of the highest precision for input and output equipment in RGB and CMYK modes and for aligning various workstations. |
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According to the company, the device is supported by most RIP and Profiling Software, Compatible for Macintosh and PC. It is available in 2 versions: - Spectro LFP RT: (transparent and reflective media, 2 and 6mm
measuring aperture) - Spectro LFP Basic: (reflective media and 6mm measuring aperture only) which is easy upgrade from Basic to RT version. BARBIERI’s spectrophotometer comes with a special measuring software ( Profile-Xpert Gateway) which allows to measure every kind of targets. |
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It is learnt that there are two types of spectrophotometers - single beam and double beam. A double beam spectrophotometer analyses light intensity among two light paths - one containing a reference sample and the other one is the test sample. A single beam spectrophotometer measures the relative light intensity of the beam before and after a test sample is inserted. Although comparison measurements from double beam instruments are easier, single beam instruments can have a larger dynamic range |
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According to researches, traditional visual region spectrophotometers cannot detect if a colorant or the base material has fluorescence. This can make it difficult to manage color issues if for example one or more of the printing inks is fluorescent. Where a colorant contains fluorescence, a bi-spectral fluorescent spectrophotometer is used. There are two major setups for visual spectrum spectrophotometers. |
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The most common spectrophotometers are used in the UV and visible regions of the spectrum, and some of these instruments also operate into the near-infrared region as well. |
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According to the company, visible region 400-700 nm spectrophotometry is used extensively in colorimetry science. Ink manufacturers, printing houses, textiles vendors, take readings in the region of every 10- 20 nanometers along the visible region, and produce a spectral reflectance curve or a data stream for alternative presentations. These curves can be used to test a new batch of colorant to check if it makes a match to specifications. |
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The company also provides downloadable softwares such as Profile-Xpert Print Pro, meant for profile creation of CMYK, RGB and Grayscale output devices (Mac and PC). It is supplied with optimized setups for different print applications (UV, solvent-, photo-, offset printing). |
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Its features include: Ink saving functionality and UCR, GCR adjustments, Flexible personalization of perceptive gamut mapping, Optimized for non standard colors used in UV, textile, ceramics and industrial printing, Profile creation for different light situations, Averaging of multiple measurements, and Optical brightener correction |
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Profile-Xpert Print 3C: It is an application for creating RGB output device ICC profiles. Profile-Xpert Print 3C uses the measurement file and the target definition to create a profile, establishing in the profile an equivalence between the RGB device values and the actual colors printed by the device. When saving the profile, the user can select the default rendering intent and populate all the descriptor fields defined in a ICC profile. |
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Profile-Xpert Print 4C is an application for creating CMYK output device ICC profiles. It is identical to Profile-Xpert Print3C. In addition to all of the many features described above, the CMYK application (Print4C) offers a very complete range of ink utilization parameters to control: total ink limit; maximum black; black starting point; black curve shape; GCR in grays; and GCR in colors. Profile-Xpert Print 4C has all the same great features of Profile-Xpert Print 3C. |
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Profile-Xpert Display is for application for calibrating and profiling any type of display (Crt and LCD). Users can set the white point to standard values, a wide range of Kelvin values, or measure a viewing light and calibrate to it. A wide range of gammas is supported. Furthermore the software allows you the verification of stability and accuracy of your monitor. After the profile is created, resulting curves show the display calibration and provide the option for additional adjustment. |
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It may be noted that a very crucial and important part in the digital printing process is the RIP software which is responsible also for correct linearization of the digital output device as well as for Color Management. For both a spectrophotometer is needed to get the colorimetric data. |
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According to the company with RIP in place, the whole printing workflow and color management becomes much easier. The spectrophotometer is driven directly by the RIP which guides step by step through the whole process. Printer linearization and ICC profile creation for all media used can be done quickly and easy.
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