The published articles are meant to primarily educate the students in printing to supplement their knowledge in the field of Printing. These are not simple Glossary of printing terms, but to the extent possible every term has been explained in brief so that it can be of some use to the students who appear in some sort of examinations and interviews.
I served the Printing Industry for over 40 years
in various capacities, a major part in an Security Printing Organization. In order not to waste the printing and paper related knowledge which I gained over years, I decided to keep them in public domain for the reason stated in prepara. Most of the illustrations - over 90% - have been generated by me to explain the terms suitably.
While I am not sure to what extent the published content will help, if the content is going to be of use to some one in some manner, I will be greatly satisfied.
Your views may be sent to me ( for my record and correction wherever needed.



- Over 400 terms-

Click on this line to read from 'A'

Friday, February 10, 2017

Effects of altering sequences of printing

The colour sequence to be followed during printing plays an important role in the reproduction of the original. In  conventional printing whether Offset or Letterpress, four different coloured inks are printed on top of each other in a specific sequence to obtain the intended tonal  and colour effects of the original under reproduction. The ultimate colour effects to match the original on print is derived by printing with Cyan, Magenta, Yellow and Black printing inks in that sequence which wherever needed turns into secondary and tertiary shades to match with the colours on the original being reproduced. Some times extra shades, which again are within the shades of the three primary colours and black  are also printed as overprint to enhance the reproduction. This is rare.

Similarly in the Security Printing process, where the design elements are  of intricate design elements likes various thickness of lines, wavy patterns, Guillosche designs etc for example the currencies, cheques, stamp papers, and labels with hidden security features, certain sequence of colour printing is followed with separate plates after the proof is approved with the same sequence. The colour sequence will not be however Cyan, Magenta, Yellow and Black as in conventional printing process, but each plate will have a rainbow of colours of entirely different hues and shades in different band widths. Since the primary colours are not used, the question of forming secondary and tertiary colours also does not arise as the shades will be entirely different in nature and the design elements criss-cross over the other to give visual shade. The colour separated plates does not have  halftone dots  in specific angle and not
printed on top of each other with Cyan, Magenta, Yellow and Black in order. This is the fundamental difference between the conventional printing process and the Security Printing process. 

Against this background  one need to understand what governs the principle of the sequence of printing the colours.  How important is to follow the sequence of colours in both the processes of printing and what will happen if they are changed ? It may so happen at times that in order to save idle hours w
henever some technical problem or the other lead to the temporary stoppage of the machines either for change of a specific colour plate, or get modified ink for smooth flow on the machine, all of which may take quite some time to arrive, some alternate actions may be taken by the printers to keep the printing continue. 

In situation when technical problem lead to the temporary stoppage of the machines either for change of a specific colour plate, or get modified ink for smooth flow on the machine, the printer will be left with two options.  Carry on  the printing with the next colour printing plate and another shade of ink both of which are readily available so that the machine idle time could be avoided. The other option would be to wait for the supply of  fresh plate and inks against the discarded plate and troubled ink. This is easier on the machine which are single colour press- printing one plate at a time. But on a multi plate printing machine this is not possible and one may have to wait till the new plates and the modified ink is received.

It is not necessary that every time the plate may be required to be changed or modified ink required leading to the temporary stoppage of the machine. It may also happen that the image on a particular plate may not be printing satisfactory and leave dark image at some spot due to some technical problem such as insignificant jerk happening due to worn out gears of the impression or blanket cylinders or even from the ink rollers at that spot. It may require replacement of the gear on machine or long period of maintenance may become imperative  to  readjust the settings and the loss of such a huge time may not be acceptable due to urgency of work.  In such a scenario  some times by interchanging the plates on the plate cylinder segment printing with darker shade having more design elements with  lower shade of colour with less design elements and vice versa the printer may notice that the problem disappear from the print. But is it a practical solution and what will be the impact in initiating this action?   See the illustration below to understand the effect of interchanging the plates between segments.

In normal circumstances the customer may agree to the moderate change in appearance of the reproduction subject to the condition that the security features are not compromised. However in the case of important documents like Currencies, Stamps, Licenses and many such vital documents, the changes may not be accepted as they may cause confusion as the visual appearance is the first step in authenticating and accepting the documents.    

Universally certain standards have been laid out for reproducing the multi colour originals in certain colour sequence since  the sequence of printing plays a vital role in determining the quality (appearance) of printed color reproductions even though few other factors too influence the quality of reproduction such as the transparency and the tack of the ink.

Theoretically speaking,  colour image is reproduced by two types of Colour models namely additive and subtractive. They are technically termed as RGB meaning additive colour with Red, Green and Blue lights while the second one is called CMYK, which is subtractive color with Cyan, Magenta, Yellow and Black using printing inks.

In the case of RGB sequence red, green and blue light are added together in various combinations to reproduce a wide spectrum of colours for the display of images in digital photography and web designs on computers. In respect of printed reproductions on paper or any other surface using coloured inks,  the accepted norm for the printing sequence is Cyan, Magenta, Yellow and then Black, shortly termed in technical language as CMYK sequence if it is four colour process of printing, or CMY if three colour process of printing.  
The CMYK is a subtractive color model, used in multi color printing on printing machines using semi solid wet inks. The printed ink reduces the light that would otherwise be reflected. That’s why this model is called subtractive because inks subtract the brightness reflected from a white background from the colours printed. Some presses even resort to printing in YCM order.
In order to understand the implications and the importance of printing in a specific sequence in both these processes, and the possible impacts of interchanging the sequence of colour printing, we need to understand the basics involved in the processes of both in brief.  
Conventional printing process:- 
In conventional printing process the first stage is to convert the multi tonal originals into several several dots on printable plates or blocks to reproduce multi colour original effect on print. Once separate plates are prepared with the design elements broken into several thousand dots of varying sizes, they are  printed over the surface one after the other with primary colours At least four basic colour separated plates/ blocks are required to print colors like cyan, magenta, yellow and black colours to match the original.   

The coloured original may comprise of many shades and the shades too in different hues and tones. For example the shades may be bluish green, darkish green, pinkish, pure blue, pure yellow or pure Red while several other shades have merged with them. Let them be any shade or colour, always remember that they fall within the range of Rainbow spectrum of colours only. Thus the effect of any shade is as closely as possible archived on print by printing them with three to four primary colour inks. This means the primary colours produce secondary and tertiary colours by different tonal values of the primary colours. Say yellow plus blue gives green. Blue plus Red gives Violet. Red plus yellow gives orange and yellow plus Red plus Blue may give black etc.  
The plates for printing are prepared with a set of four colour separated  halftone negatives/positives using colour filters and halftone screens to print yellow, cyan, magenta and black colours on paper to render the true colour image as per original copy. Once the colour separated halftone negatives/positives are prepared, so many plates and blocks are prepared and each plate or block is printed with four basic coloured inks such as cyan, magenta, yellow and black, known as CMYK. While registering the images on the substrate on which they are printed the dots in each plate sit in an angle of 15 to 30 degree from each which in technical term is called juxtaposition of dots and gives the desired colour effect as close as possible on print. 

Unless halftone screens are used, the continuous tone shades in the photos cannot be converted into printable form. And unless the screens are positioned in a particular screen angle with a difference of 30° for each colour separated negative or positive, the juxtaposition of dots i.e. printed side by side cannot be achieved and if all dots fall one upon other, it will then become a single colour dark image.

This is the basic structure of processing in the conventional printing process, whether it is Letterpress, Offset or Gravure. What will happen if the sequence of printing is changed from the accepted norms of CMYK into CYMK or YCMK ? 

Not much difference in the appearance of the ultimate print will result in. Even if there is small change, it can still be brought to the original shade by slight adjustment of the ink shades since the dots fall in juxtaposition leaving the other elements fall in their own position. See the following illustrations to understand the effect of  following  and deviating from the sequence of printing.  

Security printing process:- 
The fundamental deviation is in the basic processing  compared to the conventional printing. Security printing technique is devoid of colour separated, halftone screened negatives or positives to reproduce the original colour print. Further the primary colour inks like Yellow, Magenta and Cyan are also not used to print juxtaposition of dots to reproduce the coloured original. No screens or colour filters are used for colour separation. In short, basically the Security printing is reproduction of the coloured original in true form incorporating lines and other patterns of varying sizes and varying thicknesses on the plates or blocks sans juxtaposition of dots on print.
The photographs or portraits are first converted into elements consisting of minute dots and lines of varying thicknesses, wavy patterns, Guilloche designs and several types of straight lines and with micro letters in between.

The artist converts the continuous tone photographic image or portraits into various tonal values with lines, dots and other patterns by hand engraving them on metal blocks which is used as base for further processing. The separately engraved blocks with shades are finally joined together to form the printable image as close as possible to the original. 
How are the colour effects achieved on the reproduced prints then ? The various colour effects are not achieved by super imposing the images one on top of the other using conventional shades like Yellow, Blue and Red. The relief images from Dry Offset plates or images from plane plates of Wet Offset are printed in subdued colour combinations through a process called Rainbow colour printing in which the colours merge in a varying, uneven manner creating a spectrum of colour effect.  

In Security printing different colour shades appear wherever the design elements cross over in Rainbow printing or the design elements in single colour in the same plate have been merged in different angles to show different hue. The colours used are also subdued to ensure that they are not easily copyable  a scanner or in colour copiers.

This is the basic structure of processing in the security printing process. What will happen if the sequence of printing is changed from the approved proofs already taken in a particular sequence of printing  similar to the accepted norms of printing CMYK into CYMK or YCMK in conventional process?

Certainly the
appearance of the ultimate print will show a different result and will not match with the approved proof. Reason ? There are no fixed tertiary or secondary colours emerging from the combination to cause different hues within CMYK. The colour effects will be much different as the inks are of semi translucent in nature

The most important aspect is that the different hues appearing all over the body of the print are all  independent shades or colours, some of which are so subdued that there is no scope to show a third colour glaringly. The wavy lines and straight lines which are positioned in different angles in the design itself  gives different hues to naked eye even though the shades may be same. The lines are not in juxtaposition and instead fall on one another crisscrossing in rainbow of independent shades. The shades of the lines that fall on top of the base design elements dominate in visual appearance.  Thus altering the sequence of printing after the proof is approved with certain sequence  of rainbow colours matching to the image will show different hue on the print. the See the following illustrations to understand the position.  


 Print with a approved specific 
sequence of Rainbow colour


Appearance of Print by interchanging the
sequence of Rainbow colour

Appearance of Print by 
interchanging the
sequence of Rainbow colour
-Another example-

Finally there is another important aspect in these two processes of printing. In single colour press in  conventional printing the sheets will be printed first in one colour and then after completing printing the entire lot, it will be printed again with the second colour. However on the multi colour printing machines, the sheets will be printed with all the colours, one after the other falling on top of each in succession without waiting for the entire sheets to be printed for taking the print of other colours. The  inks being semi wet in that stage and state of body, the two or three coloured inks which fall one on top of the other in juxtaposition are able to partially get mixed with each other to show a distant second or third colour. However in the case of security print designs, the colours being independent, dull and light shaded ones, more in no instead of four standard colours, even if the design elements fall on each other they do not merge and cause a third or fourth colour element.  You can still take practical trial and see the difference in both the processes. 
All the images and design elements reproduced 
above are only illustrative models to explain 
the concept, and as  generated in computer 
by the author himself and are not the actual 
prints from any press. 

Wednesday, February 1, 2017

Print Industry - 4

Label Printing industry 

The next major sector that contributes to the growth of the print industry is the Label printing. The label printing industry is one of the fastest growing one in India and  is reportedly growing by 15 % to 17 % annually. Various types of Labels are produced both as simple labels  and with invisible security features for several products for Pharma, Food, Automobile and other consumer products. The market share of Labels can be seen from the data shown below.
(Data Courtesy: Indian Label Industry :- 

Like how no product is sold without some sort of a packing, no product too is sold without printed Label affixed over them since the tendency of the public is to first notice details on the pack before purchase of the product and therefore the suppliers  stick Labels over their products.

The Label printing is further divided into normal Labels and Labels incorporated with security features as a safeguard against counterfeiting and forgery.  Many industries demand Labels with hidden Security features to identify their genuine products in the market. Therefore there is a clamor for this aspect on Labels and thus the larger use of Labels help the print industry grow.

As said earlier there are many types of self adhesive sticker Labels produced incorporating security features for boxes and cartons to prevent sale of forged  products with counterfeit labels. The market for them is very high. Bar code Labels, Colour changing Labels, Holographic tapes, tamper evident Labels, Destructive Labels, brand protection  by invisible taggants in ink detectable through special device supplied by the manufacturer of the said label and Void seals  etc are some to mention.

The Label Printing industry is marching forward in India. As per the claims of Indian Label Printers Association, this industry has recorded highest growth rate of 19%.  According to the industry reports the Bar-coded labels are also growing by 30-35%. The Label industries growth which was around 18.42 billion Indian rupees in the year 2002-03 expected to be 1.4 billion US dollar equivalent to   67.68 billion*  in Indian rupees as on 2002-03  (* The conversion rate of US dollar against Indian rupees was approx Rs 48.40 per US dollar during 2002-03)

From the press release of Markets and Markets, India ( it is understood that :

.........The food & beverage segment is projected to be the largest market in the next five years. The demand from the food & beverage sector is expected to experience a higher growth rate, mainly because of the growing demand for packaged and branded products, and consumer awareness toward the authenticity of the product. Beverage manufacturers widely use security labels on bottles owing to the high durability, aesthetic appeal, and brand positioning which they offer. Asia-Pacific with emerging economies like China and India will drive the security labels market.............

Security labels market, by identification method, is classified into three segments, namely bar codes, radio-frequency identification and holographic. Bar codes present a cost-effective and reliable method for collecting any kind of necessary data. Bar codes are widely used by industries such as consumer durable, retail, and transportation & logistics for keeping a track of their products, as well as for tracing outgoing shipments and equipment.

Two more articles in respect of the Label industry mentioned below will be of interest to  this study. One of the two articles under the heading  'Labels and narrow web' ( reads as below

India’s Label Markets --- by Steve Katz | January 14, 2009  goes on to say that:

............Mike Fairley of Tarsus, chair of the conference sessions, kicked off the program by revealing the findings of a 2008 survey of 500 Indian label converters. The survey’s findings point toward a range of trends in the market and, according to Fairley, “ever increasing growth.” He says it’s notable to point out that in the wake of the struggling global economy, India is in far better position to weather the global economic crisis. A big reason for this, he says, is because India is far less dependent on exports than other emerging markets, such as China, for example.

“I see long term potential for high growth for the next 10 years,” Fairley says. “India is at the beginning of major retail growth. The industrial market is massively expanding and this has led to many small label companies being formed in India.”

Survey results showed that in 2008, 49 percent of converters reported sales growth of 10 to 20 percent, and 25 percent of those reporting growth of more than 20 percent. Over 84 percent of converters are printing self-adhesive labels, which is significant considering that PSA versus wet-glue labels was a major topic of conversation among the show’s exhibitors and attendees............ 

................ While brand protection and anti-counterfeiting is certainly a hot topic in India’s label market, there are other notable trends. The aforementioned survey of label converters revealed the printing processes being used, and which ones are on the rise. The survey’s findings conclude that 55 percent of India’s label printers use a screen printing process, 50 percent flexography, 35 percent offset, and 30 percent letterpress. Fairley noted that seemingly “coming out of nowhere” is the use of UV flexo, which is reported to be in use among 27 percent of the converters surveyed.....................
:- Unquote

Labels & Labeling another magazine on Labels  ( ) has published the following news.

Indian label market set to grow by 20 percent: article dated 10th June 2007 goes on to say  thus:

.........The Indian label market is set to grow by 20 percent in the next two to three years, Prof P V Narayanan, of the SIES School of Packaging in Mumbai, told the world’s self-adhesive label trade association at the FINAT World Congress in Berlin.

‘Over the last ten years India has seen its retail economy fortunes soar at ten to 15 per cent growth rates annually, to a present value of between $180bn and $230bn, and this is likely to continue over an extended period,’ Prof Narayanan said.

This growth is reflected in the expansion of its label printing industry, which last year teamed up with FINAT and VskE, the German trade association, to create the Indian-European Label Exchange, which helps set India on a target of printing at least three billion square meters of labels a year by 2009-10.

By comparison, the whole of Europe produced 5.2bn square meters of labels in 2006.

Prof Narayanan said: ‘This trend indicates that India will double its 3.2 percent of world market share to 6.3 percent in square meter terms by that time.’

Talking of the Indian-European Label Exchange, which was formed last year, Prof Narayanan said that three factors came into play – curiosity which created a lot of interest in his local market, which led to the opportunity to meet and explore possibilities which in turn promised added value to both markets.

Prof Narayanan told the Congress the business-to-business matchmaking event had been well received by the members of LMAI and should be repeated on a biannual basis. ............
:- Unquote

Security Printing : Documents and Currencies 

The Indian market for security printing was valued at $424.6 million in 2009  had reached $927.4 million in 2012, at a CAGR of 12.2% for 2009–12 period as shown in Table 3.8. Other security printing includes cheques, demand drafts, telephone bills, Exam papers and Certificates in the education sector, tickets in the travel segment, government documents like Passports, Driving Licenses, bar codes, etc. Security printing can be divided into financial (banknotes, cheques, drafts) and non-financial (stamps, passports, driving licenses, identity cards, personal certificates, dividend warrants). This also includes Currencies Printing which is a separate subject. But their growth too is responsible for the growth of the print industry as newer and newer technologies and machineries & equipments are procured in these units to march ahead of the counterfeiters and speed in delivery. Details of growth in the Currency printing is not discussed in detail  here for obvious reasons.

Other prints - irregular in nature

In addition to all the sectors and industries that aid the growth of the print industry, the leaflets and pamphlets regularly issued by the advertising sectors for various products and programs  have not been included in this study as much of them remains unaccounted and issued instantly.  Expression of huge discount sales of the products to cultural programs to social functions and other events including election time reproductions are not  viewed as regular reproductions but are  produced through small time presses or by desktop publishing at short intervals without planning. Even though the direct percentage of their contribution to the growth of  the print industry is not  accounted, the fluctuating sale of small time printing paper and the printing inks in the market will indicate that the contribution of this sector to the growth of the print industry could be anywhere between 4 -5 % as on all India level such activities are very high.