Ahmedabad-based Rajkalp Mudranalaya is well known for producing facsimile prints for the packaging and publishing industry. One of the unique aspects of its print is 10-micron printing that provides detailed images with a rich and vivid look.
“In traditional offset printing, dot patterns are spaced in a pattern. A variety of dot sizes is used to achieve tonality, density and shading. Under magnification, you can eas ily identify the dot pattern used to create the image. In the stochastic process, all dots used to create a picture are equally sized and are much smaller than those used in traditional offset printing. The dot pattern is randomized to allow a wider range of definition and dimensional effects, as well as a broader spectrum of colors. Light and dark areas are defined by using less or more dots to achieve the variations. By printing in 10 microns, we don’t create the color gamut but regain the lost color gamut. Image details that are lost in 175 lpi or conventional screening, could be retrieved and maintained through stochastic screening or FM screens. To print 10-micron stochastic screen, it takes a lot of precision and we can print it in every job,” says Kalpesh Patel, managing director of the company.
To achieve accurate and consistent color reproduction, Rajkalp has established color profiles, allowing it to replicate proofs to match the press sheets better. The color management system at the unit ensures that color is stable from one run to the next.
“If you look closely at our printed photographs, you’ll notice that they’re made up of tiny dots of four colors: cyan, magenta, yellow and black. These small dots are called half-tone screen. This process of halftoning ‘cuts off’ some information from the photograph. With 10-micron stochastic screen, the smallest printable dot helps to transfer maximum data on printed sheet, giving an extended color gamut,” Patel adds.
By using 10 microns, Rajkalp has successfully done a lot of security print jobs. For instance, Micro-text, a line or design is created using minimal text. To the naked eye, it appears as a line but when viewed with a magnifier the text is readable and can be verified. When this text is scanned or photocopied, it becomes a line.
“A few smarter features can be added during designing to make it hard to duplicate. We have a Trendsetter Quantum III platesetter from Kodak which delivers an effective resolution of almost 10,000 dots per inch. This device can render minimal text as small as 0.75 point size in the unbelievably sharp raster. A different level that is hard to achieve using the conventional methods of positives, CtCP plates or even lower-end CtPs. The power of the Trendsetter, a state-of-the-art printing machine with ultra-modern color management systems, and with the 10-micron frequency modulated halftone screens—the smallest printable dot on an offset machine in the whole world—combined with our technical know-how can produce many fantastic results,” says Patel.
For producing sharp 10-micron imaging, the printing plate also plays a vital role. Only a high-quality thermal CtP plates are capable of holding a 10-micron dot and then enabling reproduction on the right press.
Hidden images
With this method, Rajkalp’s ability to print 10-micron screen pushes the conventional method to new heights and can hide complicated pictures in the design. Invisible to the naked eye, the image or text is hidden or embedded in the design and is only visible with the help of a unique decoder screen. Scanners or photocopiers cannot recognize this hidden content, and hence duplication is not possible. There are many variations to this method and combined with smart design, it can be used very effectively as a tool to fight counterfeiting.
Holographic coating is another security feature in print that gives a 3D effect to any conventional printing on paper or board. It does not use any film, and hence it is environment-friendly and fully recyclable.
“This is a patented technology, and it is not possible to reproduce this effect without special material and technology. The equipment required for this purpose is a highly capital-intensive finishing press. It gives a similar appearance as MetPet print and stands as a viable solution. Also, it is possible to apply the effect on the entire sheet or spot areas. From the designer’s point of view, it works just like spot varnish or spot UV. In other words, a designer is free to express his or her creativity without bothering about leaving free space for the holographic sticker,” Patel concludes.
