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KODAK PREMIER HARD DOT FILMS
by
Phil Coldrick
Research and Development
Kodak Limited
Executive Summary
In 1999, Kodak Polychrome Graphics conducted an extensive survey of customer wants and needs in
regard to the performance characteristics of imagesetting and contacting film. Based on the results of
that survey the Eastman Kodak Research and Development team made a number of changes in the
company's Hard Dot technology to improve the films sold by Kodak Polychrome Graphics. These
improvements have now been incorporated into a new Hard Dot product line, Kodak Premier Recording
Films. Among other benefits, Kodak Premier offers enhanced image quality and significantly faster
processing.
The Benefits of a Hard-Dot System
The most widely used types of imagesetting and contacting film in use today are either Rapid Access or
Hard Dot. While Rapid Access films have long been embraced by the industry for their advantages in
throughput speed and performance latitude, Hard Dot films are increasingly recognized as superior for
high quality graphic arts workflows.
When contacting to plates, for example, the desired result is the transfer of all the image information
from the film to the plate. The ideal film for such an application is as nearly "binary" as possible, i.e.,
one that gives the clearest possible delineation between image areas and non-image areas. (The term
"binary" refers to the fact that computers store data as binary numbers - all digits are either one or zero.
It is this absolute either/or duality which we have in mind when we speak of the degree to which a film
is or is not "binary".)
Hard Dot films provide this binary characteristic by producing an ultra high contrast image with
extremely clear differentiation between the image and non-image areas. This differentiation is
significantly reduced in films that produce "soft" dots, such as are characteristic of Rapid Access films.
Soft dots can make tone reproduction difficult to maintain, and create a risk that some information,
particularly in the highlights, can be lost. These issues become more critical at higher screen rulings and
with the characteristic small dots employed in stochastic screening. Again, Hard Dot films offer
significantly greater assurance that the image information will be faithfully retained. Similarly the
increasing use of full pagination imposed output, which eliminates the contact film step, requires
sharper dots on the recording film to more accurately reproduce the image on the printing plate.
Exposure devices
Exposure devices also play a role in dot sharpness. Value-priced imagesetters, which in general have
lower-end optical systems, tend to image softer dots than more expensive high-end devices. This can
compound the dot-softening issues inherent in Rapid Access films. However, when these same devices
write on Hard Dot films, the films actually "sharpen" the dots, compensating for - indeed, virtually
eliminating - the disadvantages of the imagesetter's value-priced optics. (Value-priced imagesetters also
tend to use a single writing spot size, independent of resolution. This can be challenging to Rapid
Access films, making it difficult to produce smooth edged and uniformly high density dots.) Hard Dot
technology can, in short, dramatically improve the quality of output from value-priced imagesetters.
Many users also want the best possible linearity from their imagesetter/film combination. The highcontrast
characteristics of Hard Dot films naturally deliver this. Hard Dot films are in general more
linear than their Rapid Access counterparts.
Customer Needs Assessment
In 1999, Kodak Polychrome Graphics conducted a detailed study of customer needs and trends.
Approximately 130 customers were interviewed worldwide, and over 185 product or non-product needs
were identified. These were grouped into 15 categories and ranked in order of importance using a
method known as Quality Function Deployment (QFD). QFD is a systematic matrix method used to
translate customer wants and needs into measurable product characteristics that in turn can be translated
into technology improvements that will have a significant positive impact. The chart below shows how
the top five categories were ranked [Scale of 1 (least important) to 5 (most important)]:
![[chart: Customer Needs]](/white_papers/images/harddot1.jpg)
- Consistency and robustness: Under normal operating conditions, the film should give the same results
day by day, through any change of chemistry or film batch.
- Productivity: The overall film system should facilitate high productivity throughout the workflow.
Reducing the process cycle time, thus eliminating a potential "bottleneck," is one way in which film
system productivity can be increased.
- Physical Properties: Customers want a film with sound physical properties (anti-static, no curl, etc.) to
provide reliable transport of the film through the imagesetter and processor.
- Ease of Use: Customers prefer systems that require minimum maintenance and set-up.
- Image quality: Customers also want the benefits of a hard-dot system, i.e., high density and sharp
edges.
Kodak Polychrome Graphics’ Response: Kodak Premier Recording Film
Based on these customer requirements, Kodak Polychrome Graphics and Kodak's Research &
Development team created a number of technological enhancements that have now been combined into
the new Kodak Premier Recording Film and its companion developer/replenisher. This new film
system provides a number of significant benefits:
- Consistent halftone dot performance
- Faster processing with no loss of image quality
- Consistent tint uniformity from 1% to 99% across a sheet
- Very sharp small dot and kanji character quality
- Virtual elimination of "starry night"
- Lower solution usage
How It Was Accomplished
Kodak Hard Dot technology is often referred to as IBT (integrated booster technology). To provide the
high contrast characteristic of the Hard Dot films, a chemical known as a nucleator is triggered during
processing to inject electrons into the silver halide crystals in areas where exposure has occurred. This
"boosts" the processing, ensuring that all the silver halide crystals in the image areas develop, yielding
high density and clear differentiation between image and non-image areas.
The new Kodak Premier Hard Dot film employs a new, enhanced booster and nucleator system that
triggers earlier in the process. This Enhanced Booster Technology (EBT) reduces the process cycle
time by up to 33% and gives consistent dot performance over a wide range of processing conditions.
As the nucleation is more robust, it can tolerate lower replenishment rates, a wider range of film
exposures and processor throughput with no adjustment to the processor settings.
Greater Tolerance
As an example of the increased tolerance to the process, the charts below show the density and midtone
dot changes for variations in the time and temperature of development. This is a significantly
wider window than current products.
Better Processor Cleanliness
Although Kodak Premier film will give excellent results with the existing Kodak RA 2000 developer,
the best overall performance will be achieved with a combination of the film and Premier 7000
chemistry. In addition to maximizing film performance, the new developer helps maintain processor
cleanliness: it has increased stability to aerial oxidation, and it contains a new proprietary compound
that eliminates the buildup of silver in the developer tank and on the rollers.
The chart below shows the clean working performance of the Premier system. As the replenishment
rate is lowered, the tendency for the rollers and sides of the processor tank to become stained with silver
increases. With typical developers, low replenishment rates give rise to silver deposits, but with the
new Premier 7000 chemistry, the cleanliness of the processor is maintained over many tank turnovers of
chemistry, even at very low replenishment rate.
![[chart: Premier 7000 Developer: Clean Processing]](/white_papers/images/harddot4.jpg)
Other Improvements
Some of the other new technologies introduced include a new type of matte particle, first introduced in
the Kodak GEN 5 product family, which gives a very crisp appearance to the processed film and
virtually eliminates the "starry night" effect. The product also continues to benefit from the Kodak antistatic
technology, which reduces dirt pick-up and handling problems.
A Film for All Seasons
Kodak Premier Recording Film is the latest in a generation of Hard Dot products produced by Kodak to
deliver the ultimate in performance and ease of use. By combining the imaging superiority of Hard Dot
films with performance latitude and productivity approaching those of Rapid Access films, the Kodak
Premier system offers clear-cut advantages for the vast majority of graphic arts imagesetting
workflows.
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![[chart: density vs. Dev. Time]](/white_papers/images/harddot2.jpg)
![[chart: Mid-Tone Dot Size[%] vs. Dev Time]](/white_papers/images/harddot3.jpg)
