Offset printing technology | Offset lithography

Offset printing technology is preferred method for printing materials providing lower per-unit costs with the quality for larger print runs.

offset printing

VISCOSITY — RUB RESISTANCE – When printed materials rub against machinery during finishing operations or against each other during shipping or handling, the printed surface is subject to a rubbing action that tends to wear or scratch the printed surface. Water-based coatings applied over the printed surface help to improve the rub […]

AQUEOUS COATINGS-Part 2

21/10/2011 in Basic info tagged aqueous coatings / offset printing / offset printing technology by vlad682000

glossmeter device — Aqueous coatings ( water-based varnishes) are used from commercial printers for a long time giving benefits to final product and to printers in a way of higher gloss of printed product, better rub resistance, smoother feel (elimination or reduction of spray powder), and faster handling of the printed work. Basic […]

Aqueous coating-Part 1

18/10/2011 in Basic info tagged Aqueous coating / offset printing / offset printing technology / varnishing by vlad682000

blanket for printing — Although printing blankets may appear similar on the surface, there are a number of factors to consider when selecting the proper blanket for your press and printing application. Printing blankets have many physical properties that vary depending upon the manufacturer and the blanket style. Characteristics such as: print quality release […]

Printing Blanket Characteristics

13/10/2011 in sheet feed offset printing tagged blanket characteristics / offset printing / offset printing blankets / offset printing technology by vlad682000

color saturation — Problem:Solids appear to lack density Cause: Improper ink/water balance Improper concentration of fountain solution Non-uniform dampening Loss of image area Improperly set form rollers Solution: Adjust to proper ink/water balance Adjust fountain solution to proper pH/conductivity (pH 4.0-4.5) Clean brushes, flicker blades, etc; replace if necessary Adjust form rollers to […]

Color Too Weak

07/10/2011 in troubleshooting tagged cmyk rollers / color saturation / offset plates / offset printing / offset printing technology by vlad682000

plate blinding or wear — Problem:Part or all of image on plate does not take ink. Cause: Fountain solution too acidic Excessive gum in fountain solution Plate cleaners and/or scratch removers have dried on plate image Fountain system contaminated by detergent Excessive fountain solution in ink Improperly developed plates; gum adheres to image area […]

Plate Blinding Chemical

07/10/2011 in troubleshooting tagged offset plates / offset printing / offset printing inks / offset printing technology / plate blinding chemical by vlad682000

The Ink Roller Train — The ink roller train consists of an ink fountain with ink keys, an ink distribution blade and roller, a ductor roller and alternating hard and soft distribution rollers. Proper ink distribution begins at the ink fountain. If the blade is nicked, the roller surface scored or pitted, or the fountain […]

The Ink Roller Train

05/10/2011 in sheet feed offset printing tagged cmyk rollers / Ink Roller / offset inks / offset printing / offset printing inks / offset printing technology by vlad682000

Color Bar — Density is the level of darkness in a negative or positive film or print. The measurement of density is called densitometry. An instrument called a densitometer is used to measure the density. Any printing process from the most simple black and white work to complex color work will benefit from […]

Densitometer in Offset Printing Process

05/10/2011 in sheet feed offset printing tagged Densitometer / offset printing / offset printing technology / Reflection densitometer / Transmission densitometer / x-rite by vlad682000

Dot Distortion — One talks of slurring whenever the geometry of the halftone dot changes. The printed image then appears to be displaced. The round halftone dot assumes an oval form. Two kinds of slurring exist – on the one hand, in the direction of printing (circumferential slurring), and on the other hand, […]

Slurring

03/10/2011 in troubleshooting tagged Dot Distortion / offset inks / offset printing / offset printing inks / slurring / troubleshooting by vlad682000

emulsifion — Emulsion is a mixture of ink and dampening solution. In this process, dampening solution is distributed evenly throughout the ink in small droplets. The proportion of water in a “stabile emulsion” is around 20 %. If higher, then the ink’s splitting properties are reduced, and the ink flow is interrupted. […]

Emulsification

03/10/2011 in troubleshooting tagged Emulsification / offset inks / offset printing / troubleshooting by vlad682000

chalking — If the ink dries too slowly in the stack, one can speak of a lag in drying time. This may lead to an ink rub-off of the print during print finishing or during transport. The interaction between ink, additives, and dampening solution is usually to blame for lags in drying […]

Lags in Drying Time

03/10/2011 in troubleshooting tagged Lags in drying time / offset inks / offset printing / offset printing inks / troubleshooting by vlad682000