PRINTING TECHNOLOGY

The U.S. paper industry’s switch from acidic to alkaline paper, coupled with an increase in  the pH and alkalinity of municipally supplied water, has created a new set of problems for  today’s printer. Many of these problems can be directly traced to the increased presence of  calcium in the printing environment. This w rite-up will address: • Describe these new problems and how they can be recognized • Recommend steps which the printer can take to minimize their effect; • Cover the sources of calcium, and why paper an water are changing’ and • Discuss the role that fountain solution can play in minimizing calcium’s effects. • What are these new problems and how do they show up in the print shop?   Rollers    A uniform white haze develops on the surface of rollers in either the inking or dampening  trains. This interferes with the ability of these rollers to carry uniform ink and/or water films , and leads to poor...

The choice of FM halftone dot shape is important because it has an impact on plate choice, plate imaging, the aesthetics of the final presswork as well as on the lithographic performance of the press. Because there can be a wider variation of FM dot shapes than AM, this post will just illustrate several representativ e dot shape options. Each vendors' offerings can then be evaluated by using the information in this post as a guide. In an FM screen each dot is formed in a halftone cell, typically based on a grid of 16 by 16 pixels. The pixels within the cell are "turned on" in pseudo random fashion in order to form the FM dot shape or tone area. The cells are then stitched together, like a mosaic, in order to form an area of dots or tone area. Following are some basic FM screening dot shapes/patterns and their performance characteristics in use. First Order FM: Dots are all the same sizeBenefits:Image has a photographic quality even when viewed under a loupe. Oft...

CMYK is the king of color in the printing world. Four-color printing, (a.k.a. full-color printing) uses the CMYK process, which consists of four ink shades: Cyan, Magenta, Yellow and Black (sometimes called Key). 48HourPrint.com uses CMYK colors to create vivid color reproductions that will make your marketing pieces pop! Enjoy these interesting facts about fou r-color printing. • CMYK gets layered CMYK inks are semi-transparent, so instead of mixing these colors, they are layered together in the printing process. The outcome is bright, accurate, solid shades. • Benefits of basic black Any color, when lowered to the end of the spectrum, can create black, but this wastes ink. Including black in CMYK saves money and ink. Separating black from cyan, magenta and yellow in four-color printing optimizes the remaining colors and produces better results. • C+M+Y+K=Subtraction Four-color printing is often called a “subtractive” model because adding colored inks to white paper “subtracts”...

In the conventional offset printing process the dampening solution is used to separate the image and nonimage areas, that is, to prevent the transfer of ink onto non-image areas of the printing plate. The dampening solution consists mainly of water. Experience has shown that in conventional offset printing the dampening solution should have a pH value between 4.8 and 5.5 and the water used in the dampening solution should have a hardness level of between 8 and 12° dH (1.43 and 2.14 mmol/liter; 1 mmol/litre = 100 mg CaCO3 per 1 liter water). Dampening solution usually contains plate preservative agents, wetting agent, isopropyl alcohol (IPA), buffer substances, and anti-microbe additives.