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Showing posts from June, 2020

How To Make Printing Ink

  Introduction Printing ink is so much more than just the black stuff that you put on a page. It has been around for thousands of years, and it's been used in everything from newspaper presses to digital printers. As you can see, we're not talking about offset printing ink which is oil based. I want to have a little fun and talk about how you can make your own ink for your printer.  At home! Ready? Ingredients You will need the following ingredients: Soot (5 tbsp) : This is as purest as it gest. You can make the soot yourself by holding a glass up to a flame. This will allow you to slowly accumulate the soot. Water (2 tbsp): For the base of your ink, use distilled water so that you don't introduce any impurities into the mix. Distilled water is also easier to clean up than tap water because there are no minerals or residue left behind from tap water. Alcohol (2 tbsp) (grain alcohol): This ingredient works as a preservative for your ink and allows it to last for several mo

Offset vs Digital Printing - Cost & Profit Comparison

Comparing offset printing with digital printing is a much discussed topic. But the bottom line is cost and profit.  So here I would like to explain where both offset and digital intersect one another.  The bottom line is this - COST.  But let's break it down even further.  What costs keep both offset and digital printing in their respective sides of the boxing ring?  Here is a cost and profit comparison for offset and digital printing. Looking at this graph, the advantage is weighed heavily to digital printing.  Why?  Easy answer - run length.  Only 1,000 copies.  An offset press can't compete.  Let's look at each of those costs and see why. 1. Paper - As the graph shows, both have a similar cost.  But the cost is slightly higher for offset why?  Likely because of waste.  Some presses require 1,000 copies printed before they have an acceptable product.  Digital printing can achieve an acceptable product in just the first copy.   But let's turn the tables.   The advantag

How Digital Media Put Color Into Newspapers

Even just 20 years ago, the pages of most newspapers were black and white.  Today, it is an exception not to see color on the page of a newspaper.  We have digital media to thank for this.  The Effect of Digital Media on Newspapers This drive to put more color has forced the most newspaper printers to upgrade their presses and add printing units to their press lines. This involves adding printing units that can cost into the millions, not to mention the downtime for the upgrade. Typical newspaper press with full  color capabilities. The visual stimulation of color is very appealing, but the game is unfair.  Putting color into an electronic file or web page is effortless. There are virtually no limits to color appeal when going online.  It's a no-brainer.  Yet for commercial printers, it's a significant investment to keep up. Yet they MUST do it, to survive... The trend continues as color dominates our lives.  As of 2020, 85% of all pages of type that we see have some form of co

What is Fluting in Web Printing?

Fluting is the effect that happens to a web of paper when it passes through a dryer and a wavy look occurs.  This ripple effect tends to make the paper as if it it has parallel ripples.  The web offset heatset drier is the point that it happens.   Fluting is a parallel ripple effect that occurs on a web printing press. Factors that contribute to fluting. There are three main factors that are factors in the degree of fluting: Paper weight.  Much lighter uncoated stocks tend to have more fluting.  This is exacerbated when there is a lot of coverage. Additionally, the moisture content of the paper when it is produced at the mill is a factor. Ink coverage. Since paper shrinks in the web press oven, the heavier coverage areas will react differently than the areas with no coverage. The heavier coverage areas will dissipate the moisture and shrink like all other areas, but the ink will prevent it from doing so uniformly. Paper type. Uncoated lightweight stocks tend to show more fluting.  Howe

Types of Printing Processes Explained

The types of printing processes today are many. However here are explained the main processes used today: Gravure printing Offset Printing - offset web and sheetfed lithography Flexography Screen printing Digital printing Letterpress Here is each type of process explained: 1. Gravure Printing How does it work? The process of gravure printing, or rotogravure printing, utilizes an engraved cylinder.  The engraving is accomplished by means of an acid reaction to the metal.   During the printing process, the following takes place as shown in the illustration below: The indentations in the cylinder are filled by dipping the cylinder in an ink fountain.   A doctor blade then scrapes off the excess ink on the cylinder, leaving the ink inside the engraved depressions, also known as an image carrier.   The cylinder is then squeezed onto the substrate, usually paper. The impression cylinder ensures that the substrate pushes into the image carrier to absorb the ink. Gravure printing. What is it u

What Does CMYK Mean in Photoshop?

CMYK simply means cyan magenta yellow and black. These are the colors used to reproduce all colors on a printing press. Photoshop will use this color model when a product is going to be sent to a printer. Colors that can be produced through cyan magenta yellow and black are much more limited than what can be reproduced on for example, a computer monitor. Therefore Photoshop will greatly limit the range of color that is shown on an image in order for a printer to be able to reproduce it. How does CMYK Work in Color Reproduction? Below is a picture of an offset printing press.  Notice that there are four main sections of the press.  Each prints a different color: Black, Cyan, Magenta, and Yellow. (Technically, black is not a color, but adding black reduces ink consumption, produces better colors, and sharper type). Now notice this top view of this offset printing press above.  Notice the Cyan, Magenta and Yellow in each printing unit. These four colors can produce a wide range of colors

What is the CIELAB Color Space?

CIELab is the color space model used to measure the lightness, hue and chromacity of any given color. It is the most popular color model used among offset printers today and is considered the industry standard. It’s values are used to control and manage color reproduction on a printing press. What does CIELAB stand for? The first part of the acronym CIE stands for the International Commission on Illumination.  It’s actually originally in french and is written as Commission Internationale de L'├ęclairage. The second part of the acronym LAB stands for the values withing the CIELAB color model. The letter “L” stands for lightness. The letters “A” and “B” represent the position that is plotted on the color space model. Notice the position of the lightness (+L on top) and the "a" and "b" coordinates in the model below. These coordinates are used within a color gamut to show the exact color. This picture below shows the lightness factor in the color model. Histo ry of

What is Ink Density in Offset Printing?

Ink density in offset printing is the measurement light that is reflected from an ink. It is essentially the measurement of how dark and ink is. Every ink or substrate has the ability to stop or absorb light. The less light that is reflected back, the higher the density is considered to be. How is ink density measured? It can be said the more ink that is supplied to a surface, the less light it will reflect. However the formula below negates this theory.  The reason is that at a certain point, adding more ink will not make the image darker. It is measured by means of this formula: Density= log 10 1/Transmittance = log 10 1/Reflectance Here is a graph that illustrates this point.  At the upper end of the graph we see the darkness levels off.  Printers try to find the right thickness of ink so that conditions on the press are stable and proper color is achieved. Offset printers use what is called a densitometer. What is a densitometer?  A densitometer measures how much light is reflected

Web Press Operator Job Description

As a web press operator for many years, I would like to give you first hand testimony of how a job description should look.  Though press operators for any type of offset printing press have similar responsibilities, WEB PRESS operators have some unique characteristics.  So without further adieu, here is the job description for a web press operator: 1. Mounts and unmounts printing plates carefully from the web press for job changes.  Some web presses have automatic plate mounting systems.  However they still require setup. Care must be taken when mounting the plates so as not to cause scratches. Hence the word 'carefully' in the description. 2.  Loads and unloads paper rolls as per the publication requirements.  This would involve making the paper rolls ready to mount and preparing the rolls for splicing while the web press is running.   3. Makes tension and compensation adjustm ents as per running conditions. Paper is a raw material that can fluctuate as it moves through the