How was it printed? Simple ways to determine the printing method used.

The proliferation of new printing technologies like commercial production toner and ink jet presses as well as the rapid increase in quality of some traditional systems like flexography, has made it a bit difficult to determine exactly which printing method was used for a given sample. Was it offset or digital ink jet? Flexo or offset?

Here is a guide to help you identify which printing method has been used. The best method is to look very closely with a loupe at the letter forms and then confirm by looking at the halftone dots themselves. Although these images were taken at about 200x to show as much detail as possible, they are not that different than what would be seen by the human eye under a loupe at 10-20x.

Offset lithography

Type edges are sharp and well defined. The ink density is similar across the letter. The paper around the printed ink is usually clear/unprinted. The sharpness and consistent ink density is reflected in the halftone dots. Note that this same sharp appearance occurs if the halftone screen used is FM (the third image) rather than AM (second image).
Gravure

All graphic elements appear halftone screened so the edges of text show a rough halftone appearance. Although presswork color may appear rich, viewed under a loupe, the halftone dots may have a watery appearance. Individual dots may appear to have a hole in their centers.
Flexography

Flexography uses a rubber-like plate that, under pressure, transfers ink to the substrate. This results in type that often appear to be surrounded by a sharp-edged "halo." The same effect, but in opposite, occurs in the halftone dots which may have dark edges and light centers. Both type and halftone dots usually have very sharp and well defined edges. Note that this dot sharpness also occurs with an FM screen printed with flexo (third image).
Electrophotographic (a.k.a. laser toner, Xerographic)

With electrophotographic systems the image is created by depositing a powder toner. This results in a "sprayed on" appearance. Type edges are soft and there are often specks of wayward toner on what should be unprinted paper. On close examination you'll likely see apparently random Yellow dots. Those are anti-counterfeiting tags. Halftone dots have a similar fuzzy appearance.
Inkjet

Under a loupe, ink jet type has a "blocky" "chunky" edge appearance. This is caused by the low resolution/large droplet size typical of these devices (despite the claims of high dpi). Sometimes there will be the occasional "satellite" ink droplet near the letter (two are shown in the image below). Because of the way the ink is sprayed onto the substrate, halftoned areas appear to be done with an FM screen. However, unlike the FM screening used in offset lithography, there is usually no apparent pattern or organization to the dots.
Engraving

Engraving is typically used for currency/bank note printing, stamps, and sometimes very exclusive stationary. Type is very crisp and sharp. The process is capable of extremely fine detail and as a result is used to print security microtype. Halftones are usually created with line effects rather than a conventional halftone screen. Softly passing one's fingers over the printed work will reveal a tangible texture due to the raised ink.
Thermography

Thermography is commonly used on wedding invitations, letterheads, business cards, and greetings cards as an attractive alternative to the more expensive engraving process. Type has a raised surface texture similar to engraving however, with thermography type appears to be printed under a transparent coating. The low resolution of this process makes it unsuitable for quality halftone screening.
LCD display (print to screen - just for fun)

The letter "e" as displayed black against a white background on my laptop's display. Since the LCD display produces no light of its own, it requires a cold cathode fluorescent lamp situated behind the LCD panel. Electronically-modulated pixels filled with liquid crystals are arrayed in front of the light source to produce images in color. Passing the backlight through the red, green, and blue liquid crystals recreates the backlight white, while blocking the backlight creates black. Anti-aliasing of the letter helps to smooth the shape of the letter form and compensates for the relatively low resolution of the screen itself. Note that the pixels forming the image are not square but rectangles.

Optimizing images in 8 easy steps - the real basic basics

Who this post is for
Designers and people who supply images to printers and want to provide the best image possible without a lot of technical complication. Also, printers who receive poor quality images who want to help their customers tweak images to get a better result.

The software
I'm using PhotoShop CS3, but any image editing software that is capable of doing these basic manipulations will work.

The image
I'll be using this image:because it has, I hope you can see, some obvious color problems. The image is from the daughter of make-up man Harry Buchman who worked on the movie "Jaws."

The 8 basic steps
There are many ways and tools that achieve the same or similar results - most are very simple, but like anything they can be made more complicated. This following is a basic, pragmatic, method to getting better images for reproduction.

These are the 8 steps:
1) Check the computer monitor display to make sure that it is representing the tone scale correctly.
2) Check the computer monitor display to make sure that it is representing neutrals correctly.
3) Check the image resolution.
4) Set the color target.
5) Adjust color
- with an "auto-correction".
- with a manual correction.
6) Set Black and white points.
7) Adjust contrast.
8) Sharpen image and save (under a new name).

Step One - the tone scale
Download this graphic and open it in your image editing application:You should see a 21 step ramp going from 0% on the left to 100% black on the right. The black should look black and the white look white. You should be able to distinguish every patch of grey separate from each other however it is acceptable if the last two patches (95% and 100%) blend together.

Step Two - neutrality
The patches of grey in the graphic should all look neutral.

If your display passes #1 and #2 then you're good to go. If not, you may need more sophisticated help.

Step Three - image resolution
Check the image resolution. Typically the image size is based on a resolution of 72 pixels per inch (a.k.a. 72 dpi):This image is sized at 8.333" x 5.625" at 72 pixels per inch. 72 pixels per inch is pretty standard for web pages. For printing, a higher resolution is required. Changing the resolution of this image to 300 pixels per inch with "resample" not selected: shows that this image is only suitable to be reproduced in print at a size of 2" x 1.35". An image resolution of 300 pixels per inch (a.k.a. 300 dpi) at 100% reproduction size is quite standard for print application.

Step Four - set the color target
This tells the image editing application what the intent, or final destination, of the image is and helps it to display the image correctly. The color target is embodied in a color profile.
The two most common color profiles used are:
1) sRGB - which is used for images destined for the web or printed on desktop inkjet and photofinishing printers.
2) Adobe 1998 - which is used for images destined for print reproduction.By default, most digital cameras embed the sRGB profile. It can be reassigned to the Adobe 1998 profile if the destination is a printing press.

Step Five - adjust color
Auto-correction
Many image editing applications have an auto-correction capability:Sometimes that will give an acceptable result or one that can be a base for further work:Auto-correction tends to work best with images that contain a great variety of colors.

OR

Manual-correction
Manual color correction takes four steps:
1) identify neutrals
2) neutralize mid-tones
3) neutralize shadow-tones
4) neutralize highlight-tones

This image contains several likely neutrals:The highlights on the water, the midtones of the beret, the shadow-tones in the darkest part of the vest.

Use the eyedropper tool to measure the RGB values of the mid tones in the beret:The eyedropper indicates that the RGB values in this part of the image is:
R 131
G 71
B 60

The large number for RGB relative to the G and B values indicates that the image has a red cast (too much red). To be neutral grey the RGB values should be similar. By adjusting the RGB color values so that they are similar makes the mid-tones represented by this area of the image neutral:It's not important that the RGB values are absolutely identical - close enough is good enough.
In this case the final RGB values are:
R 81
G 87
B 85
Note that the color adjustment is balanced in that Red is lowered while Green and Blue are increased.

Repeat the color adjustment, using the same procedure for the highlights and the shadows.

The result:
Step Six - adjust black and white points
Use the "eye dropper" tool in concert with the "Show Info" dialog box to get the RGB values of the specular highlights. Highlights that should be absolutely white with no detail:Pure, no detail white should have RGB values of 255 each. This image's values are:
R 242
G 235
B 235
Which means that although they may appear white - the highlights are actually grey. Adjusting the highlights using the "level adjustment" option sets the highlights to their appropriate values:The same thing would then be done to the darkest black in the image which should be close to:
R 0
G 0
B 0

The result:
Step Seven - adjust contrast
Adjusting contrast changes the relationship of the tones of the image making it appear "harsher" or "softer. The "Curves" menu option is used to alter contrast:
Step Eight - sharpen image and save (under a new name)
The final steps are to "sharpen" the image (of which there are many different methods):In general, images destined for the web should be sharpened enough so that they look "natural". Images destined for print should appear slightly over-sharpened, a bit harsh looking because halftoning has a bit of a softening effect on images.

So, following these "simple" 8 steps, here's where we started:And here's where we ended:
Obviously more work could be done on the image. Other, more sophisticated, methods could be used. However following these simple 8 steps should provide much better results for those people who don't want to get too technically involved.

The Wayback View – The Syndicate - 1940

How feature writers and journalists distributed their articles to newspapers and magazines in 1940.
Please press the play arrow to view the video. Note that it may stop for a moment while the video buffers in the background.
The video includes a short clip of a journalist bashing away at a typewriter. Interestingly, when I was in high school during the early 1960s, I was not allowed to take typewriting classes because I was a boy. Typewriting was apparently "women's work" and only girls could enroll in typing classes. This infuriated my father, since, as a member of the British military police, he had to learn to type in order to fill out his reports and thought that everyone should be able to use a typewriter. In the wisdom of the day, the school enrolled me in a technical drawing class - which girls were not permitted to take.

TechTalk

Being an artist by nature and by education, the first thing that struck me when I joined Creo - other than the slogan "runs with scissors" printed on a fellow employee's t-shirt - was the language spoken by the engineers. Well, not the language actually, it was rather the words they used. Engineers insisted on using words precisely. Sloppy talk was taken as a reflection of sloppy thinking. And if there is one thing that engineers hate more than a lack of duct tape, it is a lack of clear, logical, discourse with the proper use of words chosen for their precise meanings. To me it seemed as if they had a different word for everything. So, to give you a feel for this engineering lingo, here are a few everyday items described using the engineer's unique jargon.

Portable compressed-graphite field plotterThis example of inscriptive technology is a dactylically manipulated lignin/cellulose-encased crystalline carbon allotrope allowing shear force deposition for semiotic and representational modification of planar compressed-cellulose substrates.

Dynamic load impact deviceThis is a manually activated, analog tactile/optical feedback-controlled rapid-deceleration iterative inelastic-collision generator for short-range ferrous cylinder bonding for application in voluntary fabrication, materials manipulation, and environmental modification.

Stereoscopic Image Correction SystemThe SICS is a user-installable, collapsible, free-standing cranially positioned pre-corneal refractive binocular visible spectrum optical compensator array of tandem acuity enhancing fixed-focus molded-polymer- or extruded-metallic-mounted fused silicate disks for macroscopic object recognition and text resolution applications.

Two-dimensional sociocultural referential logogramOf course the engineers also required that precision in word usage must also extend to the captions used in Powerpoint marketing presentations to help ensure that prospective customers would receive clear and unambiguous information about the topic being presented.

While engineers will babble on using their esoteric phraseology I do take comfort in the fact that my fuzzy discourse (as daily speech is called in artificial language circles) is still beyond the understanding capabilities of the most sophisticated computers - and often, as they were quick to remind me, by engineers as well.

(Posted with thanks to Edward Tenner)

Choosing a CtP - some considerations

Focussing laser energy
The laser system that exposes the plate in a CtP system has an impact on the consistency of the halftone dots that make up the image on the plate and therefore the consistency and integrity of the final presswork. The more well focussed, and hence sharper, the beam of exposing energy the more consistent the resulting halftones will be.
The four main ways that laser energy is focussed on a CtP device in order from basic to most sophisticated:

1) Depth of field. This is the method most often seen used in internal drum CtP machines and film imagesetters. It is similar in concept to how depth of field works in a camera. Although a lens can precisely focus at only one distance, the decrease in sharpness is gradual on each side of the focused distance, so that within the depth of field, the unsharpness is imperceptible under normal conditions. Typically requires constant calibration to maintain imaging consistency.

2) Hard focus. The laser is focussed for the particular plate when the CtP system is initially set up. This method is not able to cope with issues of variations in plate media thickness or as plate surface to exposure focus point changes. Hot spots and/or banding may appear.

3) Auto focus. The laser does an auto-focus for the particular plate each time just before actual imaging begins. This method is not able to cope with issues of variations in plate media thickness or as the plate surface to exposure focus point changes. Hot spots may appear.

4) Dynamic auto focus. The laser continuously adjusts focus for the particular plate during actual imaging. This method is able to cope with issues of variations in plate media thickness or as the plate surface to exposure focus point changes. Hot spots are unlikely.

The "tape test"

To get an idea as to how well the focussing system is on a particular CtP device, simply make a large "X" using Scotch tape/Sellotape on the back of the plate. Image a 50% halftone screen across the entire plate. Remove the tape and process the plate.If, after processing the plate, the tape is visible in the 50% flat tone patch then you know that any variations in plate thickness, or plate surface to exposure focus point, that is equal or greater than the thickness of the Scotch tape/Sellotape will result in variation in halftone screen tones and therefore presswork. It's unlikely that in day to day production that you'd stick tape to the back of a plate before exposing it, however it is quite possible for a small piece of debris to land on the CtP drum or back of the plate during pre-exposure handling.

Ideally, the imaging integrity of the best system would not be compromised by the tape on the back of the plate and all you will see is a large flat 50% tone - no visible "X" pattern.

During the CtP manufacturing process the geometric accuracy of the CtP drum on which the plates will eventually be mounted and imaged is measured.
Geometric compenstion
Imagine a grid wrapped around the CtP's imaging drum.

In a perfect world the grid would have perfect integrity.

In reality - the drums are never perfect cylinders.

For those CtP devices that have this capability, geometric correction distorts the bitmap that will be imaged on the plate in order to compensate for differences in the geometry of the imaging drum on the CtP device. Geometric correction also provides CtP device to CtP device integrity so that the plates from different machines will be as identical as possible.

Thermal compensation
Aluminum plates expand and contract with temperature change as much as film does - about 0.5mm across a 1m plate (typical 8-page size) for every 5°C (9°F) temperature change.
That 5°C change in temperature will result in a half row of dots @ 175 lpi misregistration plate to plate which can result in the need for the shop to reimage all four plates in a process job even if only one is actually needed.
Plate imaged twice at different temperatures. Without temperature compensation, the change in plate size due to the ambient temperature change results in a misregistration of the image.
Thermal compensation, for those devices that have this capability, corrects for ambient temperature variations by scaling the bitmap in such a way that it is as if the plates were always imaged at a single temperature.

QR Codes (2D Matrix Codes) - Reality check

If you're like most people in North America, you probably won't know what the above image represents, even though it is the latest craze being promoted to print service providers and marketeers.

"Matrix Codes," most popularly known as QR or Quick Response codes are essentially bar codes like the ones printed on package goods that are scanned at the merchant's checkout counter. QR codes take the notion a step further because they enable print media and web-enabled mobile media to work together. A QR code is a high-density barcode readable by smart cell phones and simple PC cams. By pointing the camera at the QR symbol, an application on the phone, or PC, opens the individual’s mobile browser and instantly connects them to a designated Web page without them ever having to type in a URL or promotional code - they just point and go. By scanning the codes, one can not only access websites but images, personal information, make phone calls, play a video, and send text messages.

QR codes are already a big part of mobile culture in Japan (where the technology originated in 1994) and South Korea with some 40% of mobile users in Japan regularly using their mobile phones to scan QR codes in advertisements.The marketing opportunities enabled by QR codes are limitless.

Advertisers, publishers and brand owners can use QR codes to add interactivity to any print media. In Asia (and slowly in the rest of the world) they are being placed on just about everything you could imagine - and some you wouldn't think of, like tattoos and gravestones.

QR codes explained in a clip from the television show CSI: New York.
Here are just a few examples of where you can find QR codes being used today:

• Business cards
• Outdoor posters and signage
• Packaging
• Clothing
• Newspapers and magazines
• Point of purchase displays
• Event registration

The reality check - at least for North American marketeers

While there seems to be a great deal of enthusiasm for the potential applications of QR codes, the state of the technology in North America is akin to the state of the internet for people who don't have a computer, or who do have a computer but have no ISP access. Sure the technology is great, however, from a marketing point of view, you've got to be realistic about your audience.

Today, with QR codes, you're only broadcasting to a small minority of the market:

1) They must have a smart phone or a phone for which QR reader applications are available - not just a phone with a camera. Right away that eliminates some 75% of the cell phone using audience.

2) They must be aware of the significance and value of QR codes. Try asking the technophiles at any cell phone kiosk to see if they have any idea what a QR code is. So ignorance going to remove, IMHO, at least 90% of the 35% of the market that have smart phones. So now you're down to maybe 3% of the market

3) They must download and install the QR software. That's work which many people shy away from. So maybe that cuts out another 50% of the market. So now you are down to maybe 1-2% of the market being able to use QR codes.

4) From a marketing perspective, you have to ask what percentage of that 1-2% of the total market is made up of your target audience (e.g. print specifiers)? 1%, 10%, 50%? I doubt that it's even as much as 1%.

Using a message delivery system that, at best, is accessible by only 1-2% of the total market and likely .001% of a given target market is not a message delivery system that I would count on to deliver a measurable, let alone significant, marketing ROI.

So, use and promote QR codes - but don't expect them to deliver an ROI as an effective marketing/promotional media. At least not today. However, once QR readers are pre-installed on smart phones and the major brands bring more attention to the technology QR coding will rapidly move from hype to "must have."Fortunately, the cost of entry is zero. You can create your own QR Code for any website, short text message, or other information using any one of the free online code generators like the one available HERE.

Re:Print – Color Correction