Creating crazy custom halftone screens

In a previous post (HERE) I described how to make a custom halftone dot shape. In this post I'll show you how to apply a pattern to an entire image to halftone it. In this case the halftone pattern will be very coarse so as to give the final result a strong graphic look. Click on the images below to enlarge them and eliminate any moiré caused by your monitor display.

First select an image to work with. The best images for this treatment are ones that fairly contrasty and have simple, easy to recognize, image content like this one:Then create the pattern you want to use to halftone the image using a vector illustration application like Adobe Illustrator. For this example I've created a concentric circles graphic.Note that the black and white line thickness of the pattern are about equal. As usual, you will need to experiment to get the right combination of image and pattern resolution to achieve a good effect – there are no rules.

In Photoshop, open the image you want to halftone. Then open the pattern that you've created and copy and paste it into a layer above your image. Make sure the image is in greyscale mode. Create a new layer below the pattern, fill it with white and then merge the pattern with the white layer. At this point you will have two layers; one layer with the original image and above it one layer containing the pattern.
Apply a Gaussian Blur to the pattern. In the below image the original pattern is on the left side and the Gaussian Blur applied pattern is on the right:What you are trying to do is maintain the integrity of the pattern while creating a "threshold array" of about 256 levels of grey.

Next, if the pattern needs to align with any image content then position the pattern accordingly. In this case I've centered the circular pattern over the woman's eye. Then set the pattern layer to "Hard Mix" - the result will look something like this:
At this stage, if the results are too contrasty or flat, select the image layer and use the "Curves" menu to adjust the original image's contrast to get the effect you like:
Finally, when you are happy with the result, merge the two layers. Then convert the image to "Bitmap Mode" (using "50% Threshold") to make sure there are no grey levels left that might get screened by a RIP. Your result will look somewhat like this:...and ready to place in a page layout.

You can use any pattern your imagination comes up with.
For example, this one uses wavy lines:While this one uses a hexagon pattern instead of concentric circles:

Quality printing versus production efficiency

Quality, in terms of meeting customer expectations, and production efficiency are often seen as incompatible. It is either/or, you can’t have both. However, the fact is that quality is achieved by improvement of the process. Improvement of the process increases the uniformity of production, reduces mistakes, increases production effectiveness, and reduces waste of effort, time, and materials. Reduction of waste and inefficiencies, in turn, transfers work and machine hours from the manufacture of defective materials – with their associated reworks – into the manufacture of additional good products. In effect, production capacity is increased. The benefits of better quality through improvement of the print manufacturing process are therefore not just better quality, and the long-range improvement of competitive market position that goes along with it, but greater productivity and better profitability as well. Enhanced employee morale is another gain as increased pride in their work and a greater sense of security result from seeing their efforts improve the success and competitive position of the company.

Wisdom from Yogi Berra - the greatest Zen Master baseball has ever produced

Some Yogiisms to keep in mind as we approach Print 09:

"It's tough to make predictions, especially about the future."

"You've got to be very careful. If you don't know where you are going you might not get there."

"Take it with a grin of salt."

"We made too many wrong mistakes."

"I never blame myself when I'm not hitting. I just blame the bat and if it keeps up, I change bats. After all, if I know it isn't my fault that I'm not hitting, how can I get mad at myself?"

- Yogi Berra (Born: May 12, 1925)

Effective purchase decision-making

Effective purchase decision-making on, for example, investing in new equipment, can be helped if you start by looking at the problem as a four level hierarchy of needs. Make sure that each level of the hierarchy is addressed, understood, and agreed to, in order from one to four, before proceeding on to the next. Don’t confuse the levels.

The four levels are:

1- The desired impact on your business you wish the purchase will make. E.g. Increased profit, competitive advantage, attract new clients etc.

2- The benefits to your business the purchase will need to have in order to deliver the desired impact. E.g. Shorter makeready, less waste, faster turnaround, better print fidelity, etc.

3- The features of the proposed equipment or process that will lead to the benefits. E.g. Fewer steps, greater accuracy, automation, etc.

4- The technology behind the features. E.g. Laser technology, media technology, thermal compensation, etc.

In most cases, the features and especially the technology are only useful for helping to understand and prove how the benefits and the net impact will be achieved.

Secret Shopper

Large corporations often use “secret shoppers” – employees posing as customers – as an objective way to see just how well their customer service is actually performing. Why not ask one of your customers to be your secret shopper? Create a list of print buyer processes, from sales, quotation, prepress, proofing, presswork, bindery, finishing, etc., right out to final delivery. Ask your secret shopper to evaluate your company’s performance (below average, average, above average) in each area. In particular, ask them to note how your performance compared to their expectations, as well as your competition, at each phase of the process. A gift certificate for dinner or a modest discount on their next print order might prove an effective incentive.

The Way Back View - Printers rule

Printers and publishers have always looked to find ways to keep their businesses at the forefront in their customer's minds. One method was to provide them with a practical tool that would likely be used every day. In the past, giving away specialty rulers was a popular way to do this since they had markings for things like picas, points, and column widths which were of concern to print specifiers that regular rulers did not have. The rulers were usually made of wood, but not always. The Howard-Wesson Co. ruler, for example is made of brass, while the Vancouver Sun/Province ruler is plastic and the John Wilkes Press proportion wheel (yes it's not really a ruler) is solid paper.

"Click on images to enlarge."

RE:Print - "Making Money"

"Click image to enlarge"

Custom, Spot, Brand, and Pantone Colors

Custom, Spot, Brand, and Pantone colors are all examples of custom single printing ink colors other than Cyan, Magenta, Yellow, or blacK. Just like CMYK inks, they filter (subtract) light that is reflected from the substrate.On the left below is a patch of color created with 4/C process screens and on the right the same color using a single custom ink.
Custom colors are typically specified using one or more of the following:
1- a reference physical sample such as a swatchbook, color chip, or physical sample
2- a numeric value that references a swatch or color guide book
3- a formula or recipe to mix ink ingredients in order to achieve the custom color
4- a numeric value that references a color model such as CIE L*a*b*

The Pantone reference swatchbook for its proprietary custom colors, contains a numeric color reference number, sample swatches of the custom color, as well as formulae for mixing inks to achieve the selected color.
Note: There are no specific color tolerances defined by Pantone as to what constitutes an acceptable match when variation naturally occurs.

The corporate brand color reference swatchbook below, mimics Pantone's but adds acceptable "High/Low" reference samples to accommodate ink density variations that occur naturally in presswork.

The primary brands of proprietary custom color systems are:

Pantone, the dominant spot color specification system in the United States and Europe.
Toyo, a popular spot color system that is used in Japan.
DIC, Dainippon Ink & Chemicals, Inc., another common Japanese spot color system
ANPA a palette of 300 colors specified by the American Newspaper Publishers Association for spot color usage in newspapers
HKS Hostmann-Steinberg Druckfarben, Kast + Ehinger Druckfarben und H. Schmincke & Co. containing 120 spot colors and 3250 tones for coated and uncoated paper

The hues for all these proprietary colors are defined using name, ink mix formula, and (not always published) CIE L*a*b* values.

Aspects of the Pantone spot color system

Custom colors are not limited by the gamut constraints imposed by monitor displays or press gamuts that depend on CMYK primaries. About 95% of all Pantone spot colors are within monitor gamut, while only about 34% of Pantone spot colors are within the standard CMYK gamut.
This short video (click on the "play" arrow) shows 1113 Pantone colors (excluding metallics and fluorescents) plotted against the GRACoL7 CMYK gamut. Only 376 PMS colors (33.8%) are actually within gamut for four color process (at 175 lpi) printing.The Pantone GOE color library is very similar to the original Pantone spot color library in that respect since most of the GOE colors fall between the original Pantone colors.

The Pantone spot color library was never designed, nor intended, to be used as a way to specify colors that will be printed using 4/C process CMYK. As a result, because of the gamut differences mean that 4/C process simulations of the Pantone library will, can only provide an approximation and in the majority of cases, deliver disappointing results.

At left a 4/C simulation of the Pantone spot ink color at right.
Some key notions:

1- The CMYK recipes for Pantone spot colors are generic approximations. They do not reflect regional print color standards, nor individual printshop color.

2- Approximately 66% of the library is out of gamut for 4/C process.

3- The specific colors in the library are based on ink mixing formulae - not target CIEL*a*b* color values. The CIEL*a*b* color values included with some applications, e.g. Adobe Photoshop, are only included as a courtesy to assist with conversion to CMYK – they are not the target for the color itself.

4- The Pantone Goe library is not intended to replace PMS but to supplement it (PMS library is ~1089 colors vs Pantone Goe’s 2,058). Pantone Goe spot colors are primarily “’tween” colors and about 400 colors overlap with the original Pantone spot colors.

5- There are no published specifications for acceptable variation of a Pantone spot color due to natural variation on press. Each printer/specifier/customer must determine their own color tolerance specifications.

6- The RGB values in the GOE swatchbook are actually sRGB values-I.e. not a typical printing color space.

Custom/Spot colors in the pressroom
1- CMYK inks are formulated to ISO specifications - there are no ISO Spot ink specifications. This may cause variations in the final color when the inks are prepared at different geographic locations.

2- CMYK inks are designed to overprint (wet trap) - Spot color inks designed to print isolated (dry trap). This can cause unexpected results with overprinting unless they have been specifically custom formulated to wet trap.

3- CMYK inks are transparent - Spot inks are typically semi-opaque.

4- CMYK inks have defined density (ink film thickness), dot gain and trap targets - there are none for Spot color inks.

5- Pantone spot colors are generally not formulated to be halftone screened. Some colors, as a result of the pigment grind used may appear grainy, especially with high lpi AM/XM and FM screens. If the custom spot color ink will be screened, it is best to confirm with the ink supplier that the ink formulation is suitable.

6- Pantone spot colors are often not mixed by the ink vendor, or printer, using the actual official Pantone base colors. This may cause color shifts due to the different spectral qualities of the base inks used (metamerism). To help ensure color consistency when printing at different locations, try to make sure that the base inks used to create the custom color are the same and from the same ink vendor.

7- Spot color inks are typically multi-pigment which may cause unexpected color shifts under different lighting conditions (metamerism).

8- Because of their ink composition, some custom spot colors may shift dramatically when heat is applied or when laminated. Always test before using on a live job.

9- Ink draw-downs, or pulling samples of ink on paper, tests the color of an ink mixture by spreading a thin film of ink on paper with a spatula or by using a tiny tabletop press, generically called a "Little Joe," that holds a 4×6´´ offset printing plate. By using real ink on the paper intended for the job, users get a good prediction of how that ink will look on the actual substrate, allowing adjustments in color and paper selection well before press time. However, since the tabletop press does not use water, as is used on the proper offset press, there can be subtle differences in how the spot color will actually look in the final presswork especially if the spot color will be halftone screened.

Some best practices and tips – primarily for designers and brand owners
1- Wherever possible use/insist on Pantone/Goe base inks to mix Pantone spot colors.

2- When developing custom/brand colors, it is best to use CMYK inks that conform to ISO 12647-2 as the primary base colors. Although this reduces the range of possible hues, it will allow 4/C process printing to simulate the spot brand color accurately in print applications where the spot color cannot be used.

3- When developing custom/brand colors make sure that the ink formulae contain information about the ink vendor of choice.

4- Formula-based custom/brand colors should include reference CIE L*a*b* values. The CIE L*a*b* values should be the target for color and take priority over sample swatches.

5- Custom/brand colors should include a specification for acceptable defined with either a high/low density range or a CIE L*a*b* DeltaE value. Providing a swatch guide with holes through it as in this example:allows users to place the swatch over the press sheet to more easily confirm the color match.

6- RGB values associated with custom/brand colors should specify the source (e.g. sRGB, Adobe 1998, etc)

7- Beware of the effects of optical brighteners used in paper. If proofing paper and final substrate don’t have equal level of optical brighteners then color will probably not align between them - especially in pastel spot colors.

8- The amount of optical brighteners, as can be seen in the below image taken under blacklight, that is used in the Pantone GOE guide (at left in the below image) is higher than in the standard Pantone swatch book (at right below):Because optical brightening agents can fade quickly under normal lighting conditions, this may reduce the integrity of the colors displayed in the GOE guide more quickly than the standard Pantone swatchbook. Therefore, store swatchbooks away from light.

9- The "white" ink used in pastel Pantone and other custom colors is essentially a varnish. As such it will yellow with age and cause a color shift.

10- The only proof of presswork is actual presswork - all off-press proofs share some degree of compromise - especially when proofing spot colors. Press proof whenever possible - especially when the spot colors will be halftone screened. Include any special finishing (e.g. coatings and lamination). Always clarify whether spot colors represented on proofs are valid for color or just place holders. Treat draw-downs of spot color screen tints with skepticism. Treat inkjet proofs of spot screen tints with suspicion and proofs showing spot color overprints with humor.