Paper Chase - Mike McNamee Laying the Trail

In your Editor's previous life with 'Digital Photographer magazine' one of the most successful features was one on inkjet art papers. Indeed requests are still made for copies of it. That was three years ago and so it is timely for Professional Imagemaker to take a look at the subject of paper and all that goes with it (and on it!).

Many things have changed in the 3-year intervening period. For one thing usage has risen dramatically. In 2000, 65 billion sheets of inkjet paper were sold; this is predicted to rise to 97 billion sheets in 2005 - so much for the paperless society. Pigment dyes are now more common and their gamut and quality have improved to the extent that they provide formidable opposition to their dye-based cousins in terms of colour quality. Along with the change to pigment has come longer lifetimes in terms of fade resistance. We are not presently going to consider dye-based inks in the same depth as pigment as we are wary of considering them a suitable medium for prints that are to be sold to clients - time may change this perception, we'll let you know! The other thing is that this is a paper test, not an ink or printer test. We have to limit the number of options for our tests and have fixed upon the Epson 2100 and the Epson 7600 using either Matte Black or Photo Black ink as appropriate. In terms of providers, Epson has risen to a position of dominance in the printer-manufacturing sector and continues to strengthen. Although papermaking is many centuries old there have been a number of advances in the way it is prepared for inkjet use. Resin coatings have been migrated from the silver image materials to inkjet papers, thus saving the bacon of companies such as Ilford, who are now the largest inkjet paper maker in the world. Traditional art paper makers such as St Cuthbert's Mill have developed inkjet products by marrying their substrate skills to the coating skills of others such as Kentmere. Ink formulations have to be matched closely to the paper coating type or problems of smearing and non-drying can occur; ink penetration has to be optimised and keeping ozone out is a priority. One of the complications of testing and examining papers is knowing just what you are dealing with. A couple of hours on the Net unearthed more than 50 inkjet paper brands, excluding own name brands such as PC World. However bear in mind that there are only 5 or 6 mills in the world and they all make and use each other's technology - the name on the box is not the name of the mill! A a conservative estimate of each brand having 5 papers, gives us 200 papers to look at or almost 1000 prints to make. Epson though have about 30 papers, Permajet have about 15 - so these figures are probably an underestimate of the task ahead!

Testing methods

Since the first Paper Chase our testing methods have improved. Without going into all the whys and wherefores, we use the latest and most sophisticated of the error measurement parameters, the so called Delta E 2000. This has been developed by the ICC (International Colour Consortium) and its advantage is that the error values are adjusted to most closely match the way the eye perceives differences. So, for example, we are very sensitive to variations in neutral greys and the measure reflects this sensitivity. We are not as sensitive to variations in the bright blues and again the measure reflects this.We now have three ways of examining test prints:1. Controlled Colour Light booth (by eye)2. An X-Rite DTP 22 Digital Swatchbook3. An X-Rite DTP 41 Strip Reader.In the light booth we can view in D65 and D50 conditions; we also have ultra violet lighting, and tungsten. As a final check we can take the print to the window and use good old-fashioned daylight!It is the X-Rite DTP 41, which has revolutionised the way and depth at which we examine print colour quality. We have written computer code, which enables us to stream the spectrographic data right into a spread sheet and instantly perform magic sums to generate dozens of graphs which characterise the way the paper/printer/profile combination is working. The target we use is reproduced in this feature and is also available for download at www.colouraudit.com as an A4 sized RGB (1998) JPEG file. The target has a number of images and test targets as well as spectro swatches on the right hand strips. The origin of each image is annotated with the reproduction of the target later in this feature.

Testing - the Human Touch Damaged profile

Right: The damaged profile. Note the "bite" out of the gamut in the cyan part of the spectrum.

In spite of the sophistication of our colour analysis it is still vital to have a human examine the finished test print. This sometimes throws up surprises, both good and bad. Prints with poor statistical data can sometimes look quite good and vice versa. Skin tones, for example are intolerant of contamination with green. Dark tones are quite tolerant of big shifts in hue simply because we can't see them in a dark colour. At the other end of the scale a shift in a mid tone grey will be instantly picked up by any normal-visioned observer. We had a fine example of the need to fully look over the prints and data recently when testing an experimental paper. Everything looked quite good in the photographs but the statistics for the greens looked very dodgy. Examining the profile we had built also showed a large "bite" out of the gamut. We eventually isolated the problem to a blocked nozzle set - there was no cyan at all coming through. The profile build had done quite a good job of accommodating the lack of cyan and so the print looked half decent. After things had been fully corrected the resulting print was superb! The moral of the story is that you have to look carefully at your test print and consider each bit of the test image in turn. That is why our statistical analysis pulls out the average values but then flags the larger error readings so we can go and check them out individually and make sure that they are legitimate. A flaw in a piece of paper, although rare, will play havoc with a spectro reading.

What Matters in a paper?Different photographers will have different criteria for what is important in an inkjet paper, but here is Professional Imagemaker's list. They are graded "A" for essential (i.e. must meet the criteria), "B" for desirable and "C" for not so important. Cost for example is graded "not so important" because the paper cost is quite a small fraction of your selling cost. Obviously some prints will have different criteria depending on the image. A monochrome specialist will have maximum black, grey linearity and probably metamerism high on their list (metamerism of course is more a property of the ink set). A social/wedding photographer will unquestionably have skin tones as their top priority. Scuff resistance is more important to the non-fine art user, people who buy fine art should be used to handling their prints with care. We considered creating a graded scale to assess paper but decided against it; it would have to carry too many caveats according to use to be meaningful. You are going to have to read, make your mind up and then test. Testing is well catered for as most of the suppliers will sell you a test pack containing a range of papers. The better ones even understand what you really need and Mwords, as an example, have packs with more than two of each surface in. They provide these in the knowledge that you need about 6 sheets to even start to get an idea of how a paper behaves. Importance Rating

How should we test print?This is a serious question for a review such as this as you have to balance the needs of different uses. A baseline is needed for those who want to adopt simple routines but to really test a paper’s capability you have to profile it as well as you can. There are six ways of setting up your system and, in rising order of merit, they are:

1. Use the printer's Look-up Tables.

2. Use the Installed Profiles that come with the printer.

3. Use the paper manufacturer's icc profiles (usually from the web)

4. Have a bespoke profile made by a colour management consultant

5. Profile your own system

6. Profile your own system, measure the result and iterate the profile to "perfection"

In terms of cost they range from free for 1 to 3, between £30 and £175 for 4. Doing your own varies from hundreds of pounds to thousands of pounds and you get what you pay for - more expensive kit provides more control, although you may have to learn a lot about colour profiling in order to exploit it.

At Professional Imagemaker we are in the privileged position of being able to carry out all 6 options. The problem we have is keeping the tests meaningful and also avoiding spending all of the next few months grinding out profiles and audits for the mind boggling number of combinations. Using methods 1 & 2 above will yield a pleasant print in most cases providing you stick with the OEM paper and inks. Methods 3 & 4 may produce an improvement of a between 100% and 300% in the colour precision. Methods 5 & 6 will almost certainly improve your results still further, most of the time and with iteration you can tune selective colours (e.g. skin tones) to be exactly correct, but sometimes at the expense of other parts of the gamut.

The Standard Printer Our aim is to provide you with an indication of how a paper changes the colour bias of an image the ink put down by a standard Epson Driver, or if available, by an icc profile provided by the paper-maker. For the more popular papers we have an existing database, which shows how paper/ink combinations have fared while we have been doing consultancy work. This is invaluable as it shows the variation to be expected from one machine to another. We have, for example tested almost 100 printers about 30 of which have been Epson 7600's

The Epson 7600, 9600 and 4000 are termed D2 printers to indicate that they are manufactured to a working tolerance of less than 2 Delta E. In general we have found that this is true and all the ones we have profiled have performed extremely well. There has been one 2100 which lay outside the "normal" range - it produced a heavy green bias. It was corrected by profiling but was not acceptable before that.

Statistics from a print made with the cyan-deficient profile. Only the foliage stands out as being suspect, the massive purple error bar for Saturation in the centre of the graph is the telltale sign.

Paperchase

1. A greyscale based on the Kodak Q13 Swatch Target

2. The CMYK and RGB Primary Colours

3. The Highlights detector for determining differentiation in the pastel highlight colours, typical of some brides' and bridesmaids' gowns.

4. The Black Detector for identifying the RGB value at which shadow differentiation does not occur i.e. the point at which the shadows block up.

5. A monochrome image from a flat bed scan of a resin coated print.

6. Two images, courtesy of Fuji, which show typical skin tones. The black behind the Tulip Girl is almost fully dense, the black gloves of the other girl display the level of differentiation in the shadows.

7. Two feathered models courtesy of Epson. As well as perfect skin tones the bright feathers show the level of detail achieved by a print.

8. A very tanned bride and a lace dress for checking subtle highlight detail.

9. An Imacon scan from a 6x6cm negative.

10. A drum scan from a 6x6cm negative, hand corrected for colour.

11. A Kodak Professional PhotoCD scan from a Fuji 64T 6x6cm transparency

12. Warm dawn tones from a 35mm PhotoCD scan.

13. Kodak PhotoCD scan from a 400ASA transparency material

14. A straight digital image from a Nikon D100 in bright conditions.

15. A direct scan of autumn leaves placed on an Epson 2450 flat bed scanner.

16. A Kodak PhotoCD scan of a 35mm Fuji transparency.

17. A panoramic stitch from Nikon D100 images shot in cool dawn light.

18. Block 1. The earth/landscape tones ranging from rich warm red and browns to yellows and foliage colours. A set of sky colours is shown in the bottom row.

19. Block 2. The full range of common found skin tones. All are at typical white Caucasian Lightness values with a full sweep of hues and saturations.

20. Block 3. A full range linear grey scale.

21. Block 4. The Colours of the Macbeth Colour Checker.

We know from the data that our test bed 2100 and 7600’s perform somewhere in the middle of the expected range and therefore any variations we see with non-Epson paper is due to the reaction between the paper and the driver. We should therefore be able to give general guidelines as to the corrections that might be applied in the printer driver to bring a print back to neutrality. The reason that papers bias the image in different ways is to do with differences in the rate of diffusion of the different inks into the substrate. There is a chemical analysis method called thin layer chromatography which exploits this to effect and the writer can still recall an experiment at the University of Liverpool, when he was a schoolboy visitor, in which they took fountain pen ink (Biros were banned at the time, that's how long ago we're talking!) mixed in some gunge or other and then dipped a chalk coated glass slide into the gunge. After a few minutes, the black ink had separated into its constituent pigments (blues, greens and blacks from memory) as they were crawling up the glass slide at different speeds. If an icc profile is made for an ink/paper combination, the differences in diffusion are taken account of - change the ink or the paper and all bets are off - if the cyan moves faster into the substrate it leaves the image biased towards the complementary colour (ie more red).

One of the most noticeable effects of ink absorption is the difference between a fine art paper and a gloss paper. A Somerset Velvet paper will absorb ink into its substrate to such an extent that it will be as much as 7% lighter as a Hahnemühle Photo Rag. A gloss paper will leave the ink very close to the surface and may produce a black which is another 10% darker again. This is not necessarily to imply that one product is better than another. There are those who hold that on of the advantages of Somerset is that the ink is better protected in the body of the paper and also that the paper will not flood with ink at high inking levels, enabling more depth of colour to be obtained. When preparing a sample for fade testing the astute print-maker will try for as much ink as possible as this will deliver a better Blue Wool Rating. One advantage of RIPs is that the total ink limit can be adjusted.

The Meaning of Errors

The issue that you now have to wrestle with is that a 300% improvement in the statistics does not always make a print 3 times better looking, because you may be talking of small improvements on data that are already quite good! We have had examples during our seminars of inkjets producing work that is commercially acceptable and judged to be "OK" by the majority of observing photographers. However the statistics of some of these examples has been poor. The main problems arise when prints have to be matched as "repeats" or additions to an album. Suddenly the viewer has a reference to compare with and the differences become all too apparent. The same problems arise when mixtures of digital and conventional prints are assembled in the same album, especially if this mix is of in-house printed and externally lab-printed pictures. We are reluctant to point any fingers but we have been shown (and measured) examples of so-called matched prints, which are woefully inaccurate. We can even give you the figures - the "matched" print was 16 Delta E away from the reference sample. To put this in perspective, contract-proofing standards are normally agreed between 4 and 7; on the same scale and we expect to get the whole gamut inside about 10 every time in our day to day work. The matched print looked awful and measured awful but was still sent back to the photographer.

The upshot of the discussion is this - you are quite likely to get acceptable sets of prints without spending any additional money having colour calibration carried out. If you have to match prints between your lab and your own inkjet printer or between yourself and your commercial (4-colour process) printer or match prints with other organisations (e.g. for proofing approval) you are going to have to be profiled. How much effort you expend will depend upon what you are doing. If you only have to match a couple of prints, and you have the job under control at your end, you can match by eye and make a few extra test prints when needed. If your reputation hangs on it or you are regularly going to press then you will have to work at proofer standards.

One, more specialised, application is the reproduction of fine art. Things can go very awry in this because of metamerism. Let's suppose you are reproducing a gouache painted original. The metamerism of the pigments is going to be quite large. You then take a picture and introduce the metamerism of the camera detector. Then you make a print using pigment inks and stand the print alongside the original, in front of the artist who is likely to be your fussiest client in terms of colour anyway! What is amazing is that the job ever gets done. Sometimes the best you are going to do in these circumstances is to match visually, which is why the people who do this sort of thing for a living tend to charge quite a lot to set up the print for a limited edition run. Once you have agreed on the (compromise) colour of the image you had better make sure your profiling is well bottled down or you will have to go through the rain dance all over again!

The Measuring Kit

Paperchase

ANALYSIS IN ACTION The flesh tone data from the same paper. In a perfect world the pink, Print Values should lie directly above their File Values. Above left are the results from using the Look Up Tables in the Epson printer driver i.e. a set-up that is not optimized for a non-Epson paper. The skin tones are so desiderated that the near neutral skin tones have been pushed through the origin of the graph and into the cyan quadrant. On the right, a result for the same printer, paper and ink but this time with a bespoke profile. Here the flesh tones are just a little desiderated but the hue values are maintained (the data points have moved in a straight line towards the neutral (0, 0) point. The split of the error parameters shows that the Bespoke Profile image had flesh errors averaging 2.65 compared to 9.44 for the poorer image.

For the Bespoke Profile the other errors in the gamut were low, some of the lowest we have produced in fact. An error of 1 is only just detectable by eye.

The error level created by using the wrong profile is fairly typical. Such a print is acceptable as a rough proof but not suitable for sale as a quality item.

What is Paper? Paper is made in truly vast quantities worldwide, Rey and Co, the biggest manufacturer have more than 100,000 people on their staff. The production of paper requires International Paper to plant 500,000,000 tree seedling each year just to keep up. It is estimated that inkjet media alone will run to to 97billion sheets by 2005 - and that's just Western Europe!

While it is something we take for granted, it is also something that many people know little about. It is made from a variety of materials depending on both cost and intended use. Newsprint is made from ground wood pulp and has residual amounts of lignin which make it discolour with time. It has to be fiercely bleached and residual chemicals from this process cause it to disintegrate over long periods of time. Wood based papers are not therefore ideal for imaging making - acid free and rag papers are preferred. These are made from fibres derived from cellulose rather than lignin. The cellulose can come from grasses such as esparto or from cotton. Scrap cloth is often used to make rag paper (hence the name).

The so-called wood free papers are anything but. The wood is very finely ground, heavily bleached and often has whitener added which fluoresces mildly to make the paper whiter than white - the same trick that makes Persil washed clothes whiter than white.

The art papers have a surface coating of china clay to give a smooth, non-absorbent finish. This keeps the inks close to the surface and hence more vibrant. The glossy art papers are made by calendaring the surface with multiple passes through hot (steam heated), high-pressure rollers. Strangely, art papers are not normally used for drawing and painting, they are used for classy art books and magazines with the paper being optimized for ink-on-paper printing. The terminology is now rather old and less used to describe today's papers.

In recent times new materials have made an appearance as "paper". The classic one known to photographers is resin coated paper such as Ilford Multigrade. Here plastic film is bonded each side of a paper carrier material and super coatings are applied to the top surface to hold the "high tech" surface be it an inkjet receptor or a silver halide emulsion. In the same way that resin coated paper requires less washing because of the "barrier" to chemicals provided by the polythene, the same philosophy may be used to prevent ink running away into the base paper in the printing process. Museum curators and fine art collectors are inherently suspicious of resin coatings. Under attack from ultra violet light, the polymer coating is sometimes the first thing to yield.

Surface texture - Textured papers are only normally used for painting, drawing, inkjet printing and letter press printing. They are difficult to use with Offset Litho printing, the type used to print this magazine. When we use the term art paper we really mean fine art i.e. intended for painting and creative imaging.

The texture or tooth of the paper is a key element in giving it its feel. A size is usually applied to keep the inks or paints close to the surface. A traditional watercolour paper is often prepared for use by wetting and stretching it out to dry. Some people make paper as a hobby in its own right. This is very ancient technology stretching back to Egyptian times and papyrus (from whence the name paper is derived). Most of the quality art papers come off a mould machine rather than the Fourdrinier machine used to make huge rolls of paper. The mould machine makes rolls of paper but has a woolen felt that presses the output against the drying rollers and imprints its own unique signature to the paper. As the felt wears the texture of the paper becomes less pronounced. Other materials may be substituted for the wool felt which also imparts different characteristics. There are reckoned to be only about six mould making machines in the world, so it is hardly surprising that many papers share the same base paper. The subsequent coating process has a great influence on the final result though.

Coating Technologies - Coating is a very new area for things like inkjet printing and this is where the trouble begins! An inkjet relies on squirting a very tiny drop of ink onto the page. By tiny we mean as low as 3 pico litres. This is a very small drop indeed, you would need 34 million of them to fill a thimble. Even at the 30,000 drops per second this would take the printer well over an hour to fill the thimble - scary! In terms of spatial resolution, a new Epson spits 2880 drops in an inch run of image. The last thing that they want is for this ink to run about all over the place thus destroying their carefully arranged dot pattern. This is where the fun gets going in earnest. You have to prevent the ink running straight down the microscopically sized holes in the paper surface and out into the body of the paper. That is what happens if you print onto a photocopy paper and the result is a dull lifeless image. If you then decide to coat the paper with an impenetrable layer the ink will sit on the surface, smudge and resolutely refuse to dry. The trick is to take the ink off the surface but then stop it and hold it close to the surface. Even when you have achieved that aim you are not secure. The ink continues to diffuse into the surface overnight and the print does not look the same in the morning. Even if it does, it may still be subject to long-term migration. As if this is not enough, the different inks diffuse at different rates depending upon their chemical properties.

Fine art papers

A number of different coating technologies are now available to the paper maker. The problem for the user is the advertising men. In a desperate search for market advantage they have (as ever) ruthlessly twisted and hyped the printjargon until you just have no idea what type of paper/coating combination is before you. Their copy is littered with words like, micro, nano and pico and (wait for it !) - meso has recently appeared. Micro is a millionth, nano is a thousand-millionths, meso is between nano and micro (meso is Latin for between). So now you can have a porous coating described as microporous, but when sales slump it goes up to nanoporous and if you want to show your Latin roots you go for mesoporous!

There are a number of paper and paper coating combinations is common use. Most of them make use of the mineral Rutile, which is Titanium Dioxide Ti02 a very white powder when it is ground up. It should not be confused with titanium golf drivers or hip replacement joints, they use the pure metal as a casting material. Titanium Dioxide is used for all sorts of applications which require whiteness. Your white PVC windows for example (on your house not your PC) are a PVC loaded with Titanium Dioxide. This version is very clever as it consists of little balls of Titanium Dioxide coated first in a shell of Silicon Dioxide then an Aluminium Oxide shell and then an organic surface coating. Discovered in 1913, titanium dioxide is a ceramic and is frequently mixed with other ceramics and minerals when used as a coating medium. When a coating is referred to as a "swellable polymer" the outer coating of the ceramic balls is most likely coated with a Hydrophilic Additive (hydrophilic means water swellable).

For coatings you have a choice of four technologies

1. Cast Coated

2. Swellable Polymer

3. Microporous (meso porous, nanoporous)

4. Infusion Coated

Many matte papers are cast coated. Examples of swellable polymer are Epson ColorLife and Ilford Galerie Classic. Microporous coatings are used in conjunction with Resin Coating (RC) in Ilford Galerie Classic papers and Epson Premium Lustre. At the moment the only infusion coated paper we are aware of is the St Cuthbert Bockingford fine art paper. The overall characteristics of papers are shown in the table. Art paper requirements are governed by the expectations of artists and fine art publishers. The Fine Art Trade Guild (FATG) requirements are listed in the table as an example.

Life Issues - The advantage that swellable polymer has is that the swelling of the coating seals the surface and reduces the ingress of airborne chemicals (principally ozone and water vapour). This helps to improve fade resitance. Perversely, the down side is that the small scale of the surface porosity will sometimes reject the larger particled, pigment materials, flood more easily or not dry at all. For a dye ink, swellable coating last between 2 and 3 times longer (from c8 years out to c25 years). However, pigment inks always outlive dyes.

The Wilhelm Imaging research results indicate lives of >100 years for Epson 2000 inks, 62 years for the hybrid pigment/dye Ultrachrome inks on Somerset Velvet. Interestingly, the addition of a coating to the latter test pushes the result out to >145 years.

Left:The complexity of a Titanium Dioxide filler powder. This one from DuPont has five layers like an onion shell but each is a different material. The ability to make such complex spheres only 20 nanometres in diameter leads to the name nanoporous.

Coats Please! Just when we thought we had it sussed we received a few bottles of coating material to test. There are a number of products on the market for improving the abrasion resistance of canvas and fine art papers. While these are normally the province of the fine art publisher they are very pertinent to the social photographer who sells canvas portraits that are not behind glass. The coatings can be very tough and also provide a barrier to keep out damaging, airborne contaminants such as water and ozone. They also filter ultra violet light to the extent that significant fade resistance improvements have been reported. A result that we did not expect was that the colour accuracy is improved very substantially by the application of the coating. In our initial test, one colour audit showed a 5 fold improvement on the precision of the colour in the lightness channel. In all instances the depth of the black was substantially improved (i.e. doubled!).

This is an area that we are now investigating along with the papers. Watch this space! Paperchase

Above: A taster of what is to come! These are data for the French LANA paper, used with Epson Ultrachrome Photo Black and Matte Black inks. The application of a uv protective coating from ClearShield has richened the black very substantially. Preliminary data on the new Permajet papers showed some spectacular results. Above the excellent grey scale linearity from the Epson 2100 with Matte Black inks and a bespoke profile. The graph on the right is shown on the scale we sometimes use for showing the neutrality of a grey scale. The Omega data is clustered so close to the neutral in the warm quadrant that a larger scale would normally have to be used to examine the data - a cracking good result!

PERMAJET - NEW PRODUCTS The world moves at a frantic pace. No sooner do we put a line in the sand then more product appears. Permajet let us into a little secret just as we went to print. Three new papers are going to be launched at both PMA and Focus.

They are called Alpha - Natural White (310 gsm)

Delta - Matt Fibre (275gsm)

Omega - High White (310gsm)

In collaboration with Permajet we were anxious to see how a profile made on our 2100 machine would transfer to another machine. Accordingly we built a profile and sent it away by email for testing on another 2100 using the same batch of prototype paper.

The comparison was gratifyingly good. Although the remote machine did not reach the dizzy heights of our data, the difference was marginal and only detectable by very careful comparison and machine measurement.

The home machine delivered spectacular data. Indeed on our all time record holder's list for overall colour precision, the Omega went straight to the number 1 slot and the Delta followed it into the number 3 slot. All our data from both machines was in the top half of the all time list. We will reveal the entire data set in a proper review as part of this series, but we thought you would like to hear about it so you can go and see the paper at Focus. The highlights of the data are as follows:

Over the whole Macbeth Chart the average errors of the three papers were 5.4, 5.6, and 6.2 in Lab Delta E. Refer to the notes on previous pages and you will see that this is inside contract proof standards. The flesh tone average errors across all Caucasian tones were under 3 delta E Lab. The breakdown of the flesh errors showed that 80% of the error was in the lightness channel, the colours themselves were essentially smack on the nail! The precision of the flesh tones was mimicked (or due!) to the accuracy of the reds. The Macbeth Moderate Red and Spectral Red had hue errors close to zero, barely measurable in fact.

The maximum density of the blacks was around 17% (brightness). This is good for a matt, fine art paper, which invariably absorb more ink but almost twice as good as some data that we have on other papers. Even so it is the lack of maximum density which probably causes the profile to leave the skin tones a little light on density - all art papers do this.

The grey tone scale was good, essentially linear with no bumps in it. The neutrality was first class and all the neutral tones lay in the warm (Red Yellow) segment of the plot in keeping with the creamy warmness of the base. All the data points off the neutrals were within 2 delta E of perfect neutrality - on this scale some papers with OBA's get out to an error of 10.

The Earth Tone data were excellent so any of these papers would make a good all rounder for top class work.

Getting a professional quality print from an inkjet machine can be frustrating and expensive, particularly if the system is not calibrated. Add long high resolution printing times and your workflow suffers.

I have been extremely impressed with a new system called STUDIO introduced by Ilford, so much that I invested almost immediately when realising the long-term advantages in cost savings, ease of use, better workflow, technical backup and support. The cost of my investment would be realised in just two reasonable wedding sales.

What is it?

The heart of the system revolves around their RIP (Raster Image Processor) software, which handles printer and ICC profile management, page layout and media type, allowing multi tasking operations through a dedicated printer server. The choice of printers are the current Epson 7600/9600 or the forthcoming Epson 4000. These machines are connected to your imaging computer via a network cable, or you can run the entire system as a self contained unit by loading Photoshop onto the server.

The entire installation will cost in the region of £3995 for the 7600 set-up or £2995 with the 4000 printer. Whilst this might seem extravagant, bear in mind that full technical support for upgrades, equipment, monitor and printer calibration is free for 12 months, and would cost you a lot more if you were to buy these items individually.

So why would Ilford sell you something at a loss! It’s quite simple really, Ilford aren't in the machine market but they are probably the most prolific producer of inkjet media in the world, and they make it for the widest variety of print machinery. They envisage a long-term partnership between you and Ilford in buying specialist media to use in their system. They obviously think that you will prefer their media over other manufacturers' and will be so pleased with the results and cost benefits that you will not want to go anywhere else. The proof they say is in the eating, so…

The Media

lford make a range of specialist media specifically for use with the Epson printers using Ultrachrome ink sets. Whilst other manufactures' media (including Ilford's) are made for a wide range of printers and ink types, Ilford have manufactured micro porous media that is much finer than photo material for general inkjet use. This means that in combination with the Ultrachrome inks they can fine-tune both media and ink to a custom profile which they believe is second to none.

How it works

My workstation is my original computer system, with Photoshop installed and is connected via a network cable to the IBM print server provided by Ilford. The server has a large capacity hard drive for storing and handling the file transfer from my workstation and contains the all-important RIP software. The Epson 7600 printer is connected to the printer server via a USB cable.

Images are processed on the main computer and saved in the appropriate job file as normal, but instead of printing in the normal manner I apply an Action Command which applies any printing, sharpening, final adjustments or numbering and sends the image to the "watched" folder of the RIP software in the print server. The image is closed locally and I can continue working on the next image.

The RIP software processes images in the watched folder according to media type and selected printer, applies the appropriate profile and nests the images until it hits a minimal (user specified) paper wastage. It then starts printing automatically. If there is too much blank area then the wait until sufficient area of a paper strip is used to lessen your waste. You can however, always override any of the settings to print at any time.

The software can be set for any type of media in the STUDIO range and control any number of compatible printers. I intend to add a 4000 printer to the 7600 in order to undertake my specialist Giclée printing, preventing excessive paper handling and ink waste from changing cartridges.

epson Tom’s Verdict

The system is so user friendly that I don't even worry about it in operation and have almost forgotten it's there! It's like having an extra body in the studio to handle all your printing requirements without paying the wages. The quality and accuracy of the profiles and prints are superb (Mike McNamee confirms this in his technical study of the output on the opposite page).

The Technical Report

The system consists of the Epson 7600 or 4000 models, driven by an Ilford RIP, hosted on an IBM server (2GHz Pentium 4, 512MB RAM 40GB HD, 17" CRT). The package includes assembly, set up, a days on-site training (during which your monitor is calibrated) as well as a year's support and recalibration if needed. The RIP is provided with Ilford-developed profiles for the 4 main papers. These are a Gloss and a Pearl surface based on microporous technology for instant drying and a real photographic feel. The other two surfaces are fine art, a Matte Smooth and a textured art paper. The textured paper is a chain laid, moulded paper with the typical surface tooth of such materials, although the actual surface is unique to Ilford. Both the fine art papers are 100% cotton rag, acid free.

Colour Audit

Let the statistics speak for themselves - this was the most accurate colour audit we had conducted to date! Tom used Ilford Studio Pearl on the Epson 7600 using Ultrachrome inks and the Photo Black option. The print was made at 1440dpi using a perceptual rendering intent.

The average DE2000 error was 2.59 just creeping into pole. 12position in our grand summary (all the printers we have profiled) by five hundredths of a point. In Lab Delta E terms this translates to 4.5 average, on a scale in which 4 to 7 is set as contract proof standard. The yellow green, spectral green and spectral blue were the only colours to fall outside this standard.

In the all important flesh tones (for Tom at least) the average error was 2.65DE2000, 2.2 DE Lab. To put this into perspective we sometimes see those sorts of errors when changing paper batches! The split in the errors was 1.5 Lightness, 1.7 Saturation and 0.8 Hue. Generally the flesh tones were slightly desaturated and biased slightly towards yellow. Only one data point is measured for very dark skin tones. This had an error of 0.3, only just within the measuring tolerance of the spectro.

The largest error was in the spectral blue. This is usual as it is the one colour of the Macbeth Color Checker that is out of gamut for the majority of inkjets, especially pigment based ones. The other large error was spectral green, which was desaturated. Despite this the Earth tones were very accurate at 2.7 DE2000 average. This parameter also includes the deep, warm red-browns, which have proven difficult to profile, errors of 7.0 being more typical. Thus the social photographer can expect very accurate stones, grasses and skies to go with their near-perfect skin tones!

GREYSCALE

As might be expected from a RIP-based driver, the linearity of the grey scale is really first class. The response curve runs almost straight, right down to the maximum black of 9.4% (brightness) or 1.93 reflection density. The shadows clog at between 15RGB points and 10RGB points (Adobe 1998) which is close to a full stop more than most of the data we record.

The neutrality of the grey scale is excellent. The residual bias is predominantly cyan to cyan green. The base white of the paper is blue in D65 light by 4.7 Lab points (0.62, -4.73 to be precise) and the RIP profile shifts this towards green at the ¾ tones and almost neutral at the mid-tones. The metameric index at 50% grey is 1.7 Lab Delta E Tungsten to D65. This is very low a value which is probably aided by the neutrality of the swatch in the first place (it measured 52.6, -0.6, -0.4). The only minor flaw in an almost perfect performance is the slight roll off of the whites at the high end. Ink does appear on the page at 250 RGB points but a few more would be helpful especially in a bride's dress. However this effect would only be seen in an otherwise perfect exposure and the precision of that exposure would have to be at 2/10th of a stop or less, an almost impossible task outside of a studio.

The OBA activity on the Pearl paper is less than that on the gloss paper. The lift at 440mn just breached the 100% mark. Under uv light the difference between gloss and pearl was quite pronounced, in normal daylight it was still possible to see that the pearl was not quite as bright. The measurements were quite close at 95.71% Pearl and 96.62% Gloss. The eye can readily detect a 0.5% difference at this end of the scale. The printed picture should illustrate the difference although the tones are out of gamut for magazine print. The differences were more pronounced in the viewing booth.

Mike’s Verdict

Overall this audit is a credit to Ilford and fully supports their claims of finely tuned skin tones for the social sector operator. Whilst you pay extra for the additional hardware and service, it will seem like a good investment as soon as the optimised prints come pouring out of the printer! For all practical purposes it can be regarded as a flawless performance - a real pleasure to report upon.

Paperchase

The SWPP 2008 Convention was an outstanding success,
we have 174 days to get ready for the 2009 convention - which starts on January 14, 2009

Photo Quote: I feel all things as dynamic events, being, changing, and interacting with each other in space and time even as I photograph them. - Wynn Bullock