Ink savings using solid screening

Solid screening is a technique that reduces ink consumption (and associated costs) by punching holes – too small to be seen in the presswork – into graphics that normally would print as a solid 100% tone or color. This technique is best suited for newspaper printing where the combination of dot gain and absorbency of the paper hide the visibility of the holes in the final presswork.
In this example I've used the character "$" from the Bitstream "Vera" font**, however this technique can be used with any line/solid graphic. In order to create the holes, I've screened the letters from 100% solid to a 90% tone. The correct amount of screening back to use requires some experimentation as it is a function of the halftone screening and paper that is being used.


A - The original character (Bitstream Vera) at 10 pt.
B - The same character using the SPRANQ Ecofont*. This font is designed with holes within the letters to reduce inkjet ink consumption by approximately 15-20%. The font can also be used for offset printing, however, because of the size of the holes used, this font is limited to a maximum character size of about 12pt.
C - The same character but screened back to 90% using a 133 lpi AM halftone. Because the AM dot is quite coarse, this technique is best suited to sans serif sizes greater than 18 pt. otherwise the character become too broken up by the halftone screening.
D - The same letter but screened back to 90% using a 20 micron FM halftone. The high resolution FM dot allows this technique to be used with both serif and sans serif fonts ranging from about 9pt and larger.

For newspaper application, rather than using a halftone to screen back type, it may instead be worthwhile to develop a custom font or to modify the current publication font(s), and build holes directly into the characters in similar fashion to example "B" above.

* The SPRANQ Ecofont can be downloaded from: http://www.ecofont.eu/
** The Bitstream Vera font can be downloaded from: http://www.dafont.com/bitstream-vera-mono.font

Screening solid tone areas in order to reduce ink usage is not limited to flat tone areas or fonts (as described in part 1), the technique can also be used on halftones which are, after all made up of small areas of solid tone. Here is the original image of comedian Tony Hancock:Here is a close up of the original AM/XM halftone version of the image; (Click images to enlarge)
Here is the AM/XM halftone rescreened with a 2% AM halftone dot (applied to tones darker than 5%):A more sophisticated version of this method is used in Esko Concentric screening:
And here is the AM/XM halftone rescreened with a 2% FM dot (applied to tones darker than 5%):
Punching holes into halftones does add complexity in prepress and may not be possible with some workflows. However, it can be a useful strategy to reduce ink consumption in both black and white and color images for those systems that are able to screen bilevel halftones.

Reflect the customers you want to retain

The environment we create, personal or business, home or office, is a reflection of our preferences, attitudes, and capabilities. In order to enter new markets, attract new customer prospects, or help retain existing customers, pay a visit to their offices to see the environment they work within. Then take a critical look at your buildings, offices, reception area, washrooms – all the areas of your business that customers will see. The better your facilities mirror your prospect’s environment the more comfortable they will feel that they're "in the right place" with people who understand their unique needs and, as a result, the greater opportunity you will have of becoming their preferred supplier.

World's fastest stamper

When I was a teenager, to help earn extra money, my mother would bring home "piece work" from the printshop where she worked in the bindery department. In the evenings I would sit at the kitchen table manually stamping sequential numbers onto invoice forms using a gizmo like this:
I'd get a penny for each completed numbered invoice form. I was pretty fast, but not as fast as this lady:


Please press the play arrow to view the video. Note that it may stop for a moment while the video buffers in the background.

Product Development – how vendors develop products for the graphic arts industry

In general, a technology company's focus is on developing products that have a projected volume of sales sufficient to cover the costs of development, manufacturing, productizing, and going to market with the goal of returning a specified margin of profit.
Product development usually has nothing to do with whether the product is the right product, or the best product to address the issue, or one that is best for the industry – it only has to do with the potential return on investment for developing the product.
Product development is an expensive time consuming process and so most companies will take a rigorous, organized, approach. Sometimes it may make use of a flow chart like this one:or this oneto help all the stakeholders see "the big picture" and how the various functions fit together in the complex process of product development.
The process will also include documented "gates" or significant milestones through which the product must go through which is often represented using a Gantt's Chart like this: to track progress, delays, and missed target dates.

Step 1 - Needs Assessment.
This identifies the needs and business opportunity for a new product. Ideas for new products can come from market and consumer trends, the company's R&D department, competitors, existing customer suggestions, front line employee suggestions, salespeople, corporate spies, and trade shows. One has to be careful during the needs assessment phase because, as Henry Ford noted, “If I had asked people what they wanted, they would have said faster horses.”

Step 2 - Economic Validation.
This attempts to identify the return on investment of developing the product or the risk of not developing the product. Perhaps historical data from similar solutions might be used or a SWOT analysis (Strengths, Weaknesses, Opportunities & Threats) may be done.Sometimes it's just a WAG (Wild Ass Guess). It's also important to know how much a customer will pay for the product since it must be produced for much less because of mark-up and margins required by all the people that handle it. The discussion is specifically to make sure that the product cost (and appropriate markups) don't exceed the customers desire and ability to purchase.

Step 3 - Gathering Outside Information.
Typically, a patent search and some market research are done to ensure there are no existing barriers to the product's development. Marketing would do research on things like competitive analysis, market availability, costs of getting the product to the consumer, etc. as well as some justification (in hard numbers) as to why the product will be able to penetrate the market.

Step 4 - The Design Phase.
Here the goal is to find not just any solution - but the "Elegant Solution" - the one that's the best blend of compromise of all the conflicting requirements. This process involves conceptual design where fundamental and "big" ideas are scoped out and evaluated. Often this starts with a brainstorming session where open-minded, creative thinkers from inside and outside the company gather and share ideas for exploration and evaluation The conceptual design phase is also a time for comparing competing products against a reasonable list of requirements to see how the competition stacks up.
Step 5: Screening of ideas.
The ideas generated in Step 4 are critically evaluated by the management team to isolate the most attractive options. As the ideas are whittled down to a few attractive options, rough estimates are made of an idea’s potential in terms of sales, production costs, profit potential, and competitors’ response if the product is introduced. Acceptable ideas move on to the next step.

Step 6 - Concept Development.
This begins the principal design phase (the micro level) where the details are developed and where the fundamental engineering is done. Market research continues to analyze the viability of the product ideas. The key objective is to obtain useful forecasts of market size, overall product demand, operational costs (e.g., production costs) and financial projections (e.g., sales and profits). Additionally, the organization must determine if the product will fit within the company’s overall mission and strategy.

Step 7 - Prototyping
Prototyping is the design verification phase of product development and is used to demonstrate or prove aspects of a design. Prototyping simply takes the design from the virtual and imaginary realm to the physical world. The kind of prototype used must fit the needs of the project and to demonstrate the viability of the product - especially since there is often a significant cost involved.Fabricated prototypes are typically functional versions that may or may not look like the final product but give the opportunity to test function and prove something works. Prototyping also allows manufacturing assessment to determine the best way for the product to make the transition from design to production easier, faster and smoother. This is the "Alpha" and "Beta" phase of product development.

Step 8 - Production
The Production phase is usually, by far, the most expensive part of product development. The design needs to be fully documented with detailed drawings for the applicable parts and assembly. Service support and training are initiated.

Step 9 - Product Marketing
Marketers begin to construct a marketing plan for the product. Once the prototype is ready the marketer seeks customer input - perhaps at beta test sites. However, unlike the concept testing stage where customers are only exposed to the idea, in this step the customer gets to experience the real product as well as other aspects of the marketing mix, such as advertising, pricing, and distribution options (e.g., retail store, direct from company, etc.). Favorable customer reaction helps solidify the marketer’s decision to introduce the product and also provides other valuable information such as estimated purchase rates and understanding how the product will be used by the customer. Reaction that is less favorable may suggest the need for adjustments to elements of the products or the way the product will be marketed to prospective customers. In addition to gaining customer feedback, this step is used to develop customer testimonials and white papers. Sales and dealer channels start to be trained on the upcoming product.

Step 10 - Commercialization
If market testing and beta site experience display promising results the product is ready to be introduced to a wider market. Some companies launch products well in advance of actual availability in order to stifle the sales of similar products from competing businesses. Sometimes the product is introduced or rolled-out the product in waves with parts of the market receiving the product on different schedules, or with only parts of the total product solution being available. This allows the company to ramp up production in a more controlled way and to fine tune the marketing mix as the product is distributed to new areas.

The Wayback View – SP Plateless Offset Technology in 2000

Recently, J P Imaging, with their experimental Miracle Plate* technology, has demonstrated a unique concept – that of switching an uncoated litho ‘blank’ uncoated plate from hydrophobic to hydrophilic. The benefits of this technology, if it becomes a product, is the potential elimination of all chemicals in plate coating, organic solvents from the coating process, as well as all requirements for processing equipment and associated chemistry. It would also have major environmental benefits by drastically reducing the demand for aluminum within the printing industry.

The announcement has renewed interest in alternative ways to image plates for offset lithography. One such alternative was demonstrated as a proof of concept at GraphExpo in 2000. The CreoScitex "SP Plateless Technology" was a plate imaging system where a plate could be imaged, and reimaged, by spraying an ink receptive coating (Agfa Lightspeed) on it while the plate was mounted on press. Rather than manufacturing, cutting, and shipping plates that could be used only once - printers would just purchase the ink receptive liquid coating.

Please press the play arrows to view the video. Note that they may stop for a moment while the video buffers in the background.
This 1 minute video uses animation to explain how the direct on press ("DOP") SP Plateless Technology works.


This 11 minute video is the live demonstration presented by Doug Richardson (now CEO of General Fusion Inc.) of the CreoScitex SP Plateless Technology using a Shinohara press at GraphExpo in 2000.

The Haida mask images were my small contribution to this project.

*More info on the Miracle Plate technology is available HERE

"Know Thyself" - Which car brand are you?

From a legal point of view, when a printshop becomes incorporated it marks the formation of a legal entity that is effectively recognized as a person under the law. And, like any other person, the printshop has a "personality" – its face to the market and the customers it serves. From a marketing and sales point of view, it is very useful for management and front-line workers to have a clear and unanimous understanding of the personality that the printshop wishes to embody and project to its public. Doing so can help guide everything from investments in new equipment and services, to the decor used in the plant. It also helps set customer expectations for the experience they will have when they do business with the shop.

Which car brand are you?

Better defining and understanding your printshop's personality can be helped by borrowing a technique used in marketing - asking the simple question: "If your business was a car, which brand of car would it be and what would its personality traits be?"

Here are some (briefly) detailed ideas to get you started, each of which could be expanded to cover every aspect of your business.

BMW "The ultimate print machine." We emphasize the equipment and technology we apply to print projects. We compete on value - not on price - to print specifiers and buyers who can appreciate what we bring to the table. Our lobby is spartan and contemporary and proudly shows the many international awards for print quality that we've garnered. Our press room is a showcase of excellence.

Toyota Prius "Harmonizing quality, value, and the environment." We emphasize how our print processes meet the print quality needs of our customers while minimizing the impact on the environment. We are not the low cost provider, instead we compete on sustainable value by nurturing long term relationships rather than operating on just a job by job basis. Our lobby mingles local awards for print quality and from sustainability organizations. Our press room demonstrates our environmental initiatives with dedicated recycle and reuse areas.

SMART car "Two and four-up jobs are where we excel." We're nimble and are able to turn around jobs quickly. Although we're a small shop, we can provide much of the expertise you'll find with the big shops - and we've got a few print quality awards to show for it. We compete by providing a very personal service with great value for the dollar performance. Our pressroom is quite small so, instead, we concentrate more our customer facing areas such as our storefront, lobby comfort, and on-line print order system.

MACK truck "The long run specialist." We're the big iron - so we stay with what we do best: long press runs and contract work. Our facilities haven't changed much over the years, although we do have a few bits and pieces of the latest technology. Our customers aren't that interested in awards, but we do submit work for judging, after all it does show that we are proud of our work and it does help to cement relationships with our customers. Our pressrooms are huge and not really suited for our customers to visit - so we have a small visitor area where they can relax on the rare occasion they may need to see a job on press. Because of our size we consume a great deal of resources, and because of customer concern we will be looking into implementing some sustainability programs.

Of course there are many more cars, and personalities, to explore to help you define your own unique corporate personality.

Print in the internet age – a customer's perspective raises some questions

It's a story we've likely all heard before, however, Paul Roy, Manager of Coldwell Banker Tomlinson Associated Brokers in Washington, is particularly clear with his thoughts, as a print buyer speaking to his customers the advertisers on the shift of real estate advertising, from print (newspapers and magazines) media spend to the internet. As such this five minute video may provide some insight to help you in reviewing the clients you are currently serving with presswork that potentially may also move to the web.



Please press the play arrow to view the video. Note that it may stop for a moment while the video buffers in the background.
What percentage of your current customer base are likely to move away from your print offerings to the web in the next six to twelve months? Can you counter with reasons that resonate with your customers as to why they should remain with print - if not for 100% perhaps for some percentage of their media spend? Are there ways that Paul has overlooked where print can bring greater communications value than the web? Is the current vendor push of personalized digital print really an effective counter to the web? What marketing communications are likely not appropriate for the web and as such worth developing as a niche area of expertise.

The Wayback View – Printshop advertising in 1923

Since the beginning of the printing industry, printshops have advertised their services to print buyers - often with familiar themes.

Click images to enlarge
W.G. Briggs & Co. capitalizes on the fad for collectible postage stamp sized advertising stickers to attract the eye of potential customers.
The Rembrandt Intaglio Printing Company Ltd. addresses the issue of consistency through the run - a major concern for all print buyers – while reminding them that print quality can only be as good as the art they are given to work with. Their print sample is a duotone run at a very respectable 300 lpi.Interestingly the Rembrandt Intaglio Printing Company Ltd. was founded by Viennese engraver Karel Klic the inventor of the photogravure process in 1879.Karel Klic (1841-1926)
The Abbey Press Ltd. extolls the beauty of the art they work with while reminding the reader that, while they currently work with first-class customers, they would be glad for the opportunity to work with you.
WH Smith was, and still is, a big box supplier of stationary, office equipment, and books. Here they promote their association with The Arden Press to deliver a variety of print material – perhaps somewhat in competition with their customers.

Dutch Intaglio Printers extoll the quality of their screenless/continuous tone 3/C process printing. In this case, the collotype process delivers fidelity on par with contemporary 20-micron FM screening.
St. Clements Press Ltd. offers creative services, perhaps in competition with some of their customers, to provide a complete solution.
Spottiswoode, Ballantyne & Co. Ltd. takes a merry seasonal approach while providing timely advice that "...the Printer, of all craftsmen, must trim the sails of his "craft" to catch the timely breeze of public demand."

Ink Sequence - 4/C process & beyond

In 4/C process (CMYK) or any multi-color printing for that matter, different inks are laid down in sequence in order to build the final image. The sequence that the inks are laid down can significantly alter the final printed result. Ink sequence can also impact whether the job runs successfully or fails on press.

Printing always involves a level of compromise and the choice of ink sequence is no exception. However, while there are few "rules" and surprisingly, virtually no documented information on this topic, there are several notable factors to consider when determining the appropriate ink sequence to use for any specific application, namely:
1 - Conformance to an industry standard. For example, ISO 12647-2:2004 for process control in offset lithography standardizes the chromatic ink sequence to CMY – however, black is acceptable as either first or last down.
2 - Ink tack - the stickiness of the ink that allows an over-printing ink to stick to an already printed layer of ink.
3 - Paper absorption - both smoothness and tightness of the surface affects ink tack.
4 - Time - wet ink sticks/traps to dry ink better than wet ink traps to wet ink. E.g. unitized press (each unit lays down one ink) or common impression cylinder press (one unit lays down multiple inks) or single color presses where the next layer of ink is applied much later than the previous.
5 - Ink opacity - opaque inks hide underlying inks.
6 - Ink transparency - transparent inks combine with underlying inks.
7 - Ink coverage - the higher the coverage of an ink the less following inks are able to trap efficiently with it.
8 - The RGB to CMYK separation technique that was used.
9 - The printing method being used - i.e. sheetfed offset, flexography, gravure, etc.

In multi-color presswork the first ink down "traps" the one that follows. Tack - the stickiness of ink - is a major factor enabling inks to adhere to, or trap, one another.
In the proper sequence, the first ink down must have the highest tack. Subsequent colors have lower effective tacks, with a descending 2-to 4-point spread between them.

In this first example, a layer of Magenta was printed on a single color press. Then an overlapping layer of Cyan was printed in a second pass after the Magenta ink had dried (i.e. wet-on-dry or "dry trapped"). The ink film thickness of both colors was the same.The result is very good ink film trapping with a blue where the two colors overlap not having a bias towards Cyan or Magenta.

The second example was produced on a multi-color press. Again Magenta is printed first down onto dry paper (i.e. wet-on-dry). Then a layer of Cyan was printed onto the still wet Magenta ink (wet-on-wet or "wet trapped").While the Magenta ink film was trapped well by the dry paper, the ink trapping for Cyan was not as good due to the fact that the Magenta ink was wet, and so the resulting blue where they overlap has a decided reddish cast.

In the third example, the wet-on-wet printing method was used again, but with the ink order reversed:The result is that the blue, where Cyan and Magenta overlap, now has a decided Cyan cast. Note that this particular ink sequence is the standard for CM inks in CMYK process color printing.

Ramifications
Modern offset presses print all four (or more) inks in rapid succession, 'wet-on-wet'. The first inks down usually adhere to the paper better than later inks. In some cases the later inks can actually remove some of the earlier inks, depending on the relative tack of each ink in the sequence. Either way, the amount of one or more inks remaining on paper is usually less than would be achieved on a "dry trapping" press, or with a drying system between each unit as is accomplished by some form of inter-unit drying system, such as IR (Infra-Red) heat for conventional inks, or UV (Ultra-Violet) light for UV-curable inks.
Wet-trapping can also introduce an unstable performance in darker tones and is often cited as one of the main problems in matching multiple presses to a standard characterization data set, even when each press uses the same paper and ink.

So:

1 - Dry-trap printing processes can achieve a greater color gamut than wet-trap printing.
2 -The sequence of the primary CMY inks helps determine the color integrity of the secondary colors (RGB)
3 -Changing the sequence of CMY inks can be used to enhance/favor specific secondary colors.
4 - Poor ink trapping in 4/C printing will be revealed in a loss of gamut, color bias, lack of vibrancy/chroma, and a mottling/splotchy appearance in the secondary colors (RGB)
5 - With graded tack inks, the tack must be adjusted to reflect the ink's new position. E.g. If first down Cyan tack is 14 followed with an overprint of Magenta with a tack of 11 then, to maintain good trap, if Magenta becomes first down its tack must be adjusted to 14 and Cyan's tack adjusted 11.
6 - The further apart two ink units are on press, the better their effective trap should be. I.e. In a KCMY ink sequence, C and Y (forming Green) will trap better than C and M (forming Blue) or M and Y (forming Red).

Addendum
Below are the typical trap values (Status T, Preucil formula) for different types of presswork as well as the CIEL*a*b* values according to ISO 12647-2:
As noted, the ISO standard specifies that the chromatic inks are laid down in CMY sequence with K being either the first or last ink down. Traditionally, for most offset applications, the ink sequence has been KCMY.The preference for this ink sequence is likely the legacy of the image separation methods used in the past. Prior to today's desktop image editing applications, the conversion of RGB scans into CMYK images, was performed by software in the scanner itself. The conversion method utilized UCR (Under Color Removal) techniques to optimize the image for the press as in this example:Note that in a UCR separation, there is very little Black ink coverage compared to the C, M or Y plates. Note also that there is a large amount of Y coverage in the image, in part, because the Y component in the separation is being used instead of Black ink to grey, or darken, the image. This means that laying Black ink down first provides a greater area of dry, non-inked, paper for the Cyan ink to trap to. In a KCMY ink sequence, running the transparent, high area coverage, Yellow ink last down also has the benefit of acting somewhat like a gloss varnish to add depth to the reproduction.

In contrast, for newspaper production, Yellow is usually the first ink down with Black ink the last down:The reason that this ink sequence is preferred over a KCMY sequence is both related to the use of UCR separation techniques as well as the inks being used. For newspaper work:laying Yellow down first helps to seal the paper thus providing a better surface for the Cyan ink to trap to. Black ink last down benefits from the three previous inks sealing the paper which helps the Black ink deliver maximum blackness and contrast. Maximizing the coverage of the chromatic C, M, and Y inks and minimizing the use of Black ink in images also helped images to maintain as much of their vibrancy as possible given the poor quality of paper being used. Finally, the Black ink used for newspaper work tends to be of very poor quality compared to the C, M, and Y inks. If it was first down, it could travel down to the next printing units and contaminate them.

"A wrench in the monkey works" - GCR separations
In today's image processing workflow, the default separation method uses GCR (Grey Component Replacement) rather than UCR techniques. In addition, many newspapers and publication printers are reseparating incoming image files in order to apply GCR techniques in order to reduce ink usage and increase color stability on press (more information is available HERE). A GCR separation, like this example:maximizes the use of Black ink in order to reduce the amount of the more expensive chromatic C, M, and Y inks while delivering virtually the same final color appearance in print. For newspaper work, the use of GCR separated images in a YCMK ink sequence may lower the effectiveness of the Yellow ink to seal the paper and hence reduce the potential color gamut.

Ramification

When evaluating the optimal ink sequence for a specific application, particularly the position of the Black printer, it is important to consider the type of separation techniques that were used to prepare images for press and how those separation methods impact both ink trapping and printability.

Addendum - Ink Sequence for a two-color press

The recommended ink lay down sequence for a two-color press is: first pass CM, second pass: KY:This sequence makes CM inks wet trap which helps align the color result with that of a four-color press. Also, because the primary chromatic colors are laid down together, it facilitates color assessment. Black, being achromatic does not affect color. Yellow, being the greying component of C + Y does not effect color as much as C and M.

Adding a 5th, 6th, or more inks to the sequence also adds a degree of complication.
Note that most presses with more than four colors are run with the first units empty and available, with the KCMY inks in the last four units. However there is no standard practice, so which units are available will vary from shop to shop.

The general guidelines are:
1 - If possible, keep the process colors together in their standard order (KCMY). This is to avoid color shifts that might occur if their inter-press unit distance changes. This also helps avoid wash-ups.
2 - If possible do not move the position of the KCMY inks. This is to avoid having to do a complete wash-up of press units.
3 - If the extra color(s) will not be over-printed by process colors it would preferably be last down.
4 - If the extra color(s) are opaque and will be over-printed by process colors it would preferably be first down.
5 - If the extra color(s) are transparent and will over-print, or be over-printed, by process colors, its position should be furthest away from the color it will trap with. This is to help make it a dry-trap situation increasing print-ability and reducing mottle.
6 - Metallic inks, whenever possible, should be last down unless they are specifically formulated to be first down in order to be over-printed (e.g. MetalFX printing). Note that metallic inks are usually varnish coated and that many printers keep the last press unit available for the varnish. This may then require that the metallic ink be first down even though it won't be over-printed.

Some examples:

Spot color will be over-printed by process colors:
Opaque spot color will over-print process colors:
Metallic silver:
Hi-Fi color printing where transparent extra process color inks will be trapped with standard process inks:

The Color Atlas - helping designers to specify color

Way back when, because all their "camera-ready" art was done in black and white, designers would specify screen tint color builds by using published reference Color Atlas guides like the generic Kuepper's book which showed examples of hundreds of CMYK screen tint build combinations:Or this poster of screen tint combinations:Because they were based on, loosely defined (at the time) universal standards, the use of a color atlas, in my case, even allowed me to communicate color for presswork in countries, like China, where I did not otherwise understand the language:The prepress shop/printer would use pieces of screened film, according to my specification of X% Cyan, X% Magenta, X%Yellow, etc., stripped into flats to create the image on plate that would result in the requested color on press. Today, that specification happens in an illustration or page layout program – however the principle is the same.
Of course, a generic Color Atlas could not reflect the color performance of an individual printshop. As a result many printers would create, and provide their customers with their own unique CMYK Color Atlas like this one from Agency Press with the same screen tint builds printed on four different types of paper:As long as the creative specified their color builds according to the printer's guide in the Atlas they would have a reasonable expectation as to the color that would happen on the press. Some might argue that this is ancient technology, however, for printers who want to clearly set print buyer expectations - a Color Atlas still represents the reality of actual "ink-on-paper" performance – especially if the printer's presswork is outside of industry norms. For example, Hennegan Press:who wanted to show their color capabilities with 10 micron FM. Or Fort Dearborn in Chicago helping their customers specify 7-color process printing with their HiColour system (also FM screening):or Anderson Litho communicating their ability to mimic metallic paint for car brochures (also FM screening):or Intelligencer Printing demonstrating their metallic print capabilities in this superb brochure (also FM screening):Even with today's sophisticated color management systems, the savvy printer would do well to consider producing their own Color Atlas to smooth the color communications channel with their customers - especially if the print shop is doing work beyond the mundane standards for color printing.

Update December 15, 2009: Heidelberg has just published their own color atlas - click on this POST for details:

Naming Image Files

When I managed a prepress scanning department that handled thousands of images, I used a simple naming convention that anyone (even creatives) can use which practically made the images organize themselves - and avoided incorrectly formatted images from being placed into page layouts or used for the wrong application.

The naming convention followed this coding format:where the first letter of the image mode and the first letter of how the image was purposed are used as the first two letters of the image name. By naming image files this way, whenever a folder containing images is viewed by name, the images will be automatically grouped according to their mode which makes choosing the correct image format very simple.
It also used a descriptive name that was logical enough to be searched on. I used a date code in the name so that as the image went through the editing/revision cycle I would save the updated images with the new date in the name. This meant that I had copies of the image that tracked the revisions done to it with the most recent version of the image being the one with the most recent date in its name. This avoided using the ambiguous term "Final," "Final v2," "Latest Final" etc. in the image name.

Image mode codes:
R = RGB
C = CMYK
G = Greyscale
B = Bilevel/Bitmap
M = Monotone
D = Duotone
T = Tritone
I = Indexed

Destination/purposing codes:
P = Publication/SWOP
S = Sheetfed/GRACoL
N = Newspaper/SNAP
F = Flexo/FIRST
W = Web
D = Display Inkjet
B = Backlit Inkjet

Some examples showing how the codes are used in practice to easily identify/describe the image:

GN_Sydney_Harbor_Australia_201008.tif = Greyscale image purposed for Newspaper reproduction.

RW_Sydney_Harbor_Australia_201008.jpg = RGB image purposed for use on a Web site.

CP_Sydney_Harbor_Australia_201008.tif = CMYK image separated for use in a magazine.

B_Sydney_Harbor_Australia_201008.jpg = Bilevel/Bitmap image.

MF_Sydney_Harbor_Australia_201008.eps = Monotone/single color image prepared for Flexographic printing.

DS_Sydney_Harbor_Australia_201008.eps = Duotone/two color image prepared for Sheetfed printing.

IW_Sydney_Harbor_Australia_201008.gif = Index mode image prepared for posting on a Web site.

In some cases I would add the word "TOSS" to the image name:CP_Sydney_Harbor_Australia_201008_TOSS.jpg = CMYK image prepared for Publication. "TOSS" signified that the image could be trashed/erased if hard drive space was needed.