Understanding thermal sublimation

Thermal sublimation

4 manufacturers dominate the personal A4 color printer market. They are Canon, Epson, HP and Lexmark. Brother is trying to make a place in this quartet but it isn´t an easy task. Olivetti as well, but their products aren´t good enough to really compete. In the 4"x6" family, the market is a little more open. Because of the price of these small products and the comfortable margins made on these printers and consumables, several companies entered the game, sometimes without any previous real expertise in the domain. It would be a mistake to neglect them, however. These new printer manufacturers do not use inkjet technology but thermal sublimation.

The ink is this time created by a translucent film rolled up in the cartridge. The photo print is made after four successive passes of the sheet of paper that goes in and out of the printer. The first layer laid down is yellow, then magenta, cyan and finally a transparent protection layer. The superposition of the three primary colors makes it possible to print a photo with a detail level and accuracy as good that of a photo lab.

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A 300 pixel per inch resolution is attained with 300 heat heads per 2.54 cm line. 300 x 10 cm wide paper / 2.54 = 1181 heat points on the width of the paper.


The paper unrolls by layer stuck between these heads and the paper, the incrementing step is 1/300th inch (0.085 mm). Point temperature varies according to color intensity creating the variations on paper. The hotter it is, the more ink leaves the roll and the more intense the color shade will be. The number of possible shades per color is 256. The ink doesn’t melt but is directly transmitted from a solid state on the roll to a gas ejected to and fixed on the paper. This is why it’s called sublimation.

The color order is most important. The temperature required for yellow is superior to the one required for magenta, which is greater than that required for blue. This also avoids the possibility of melting the previous ink layer that is already on the paper. Gas repartition is homogeneous and this is the reason for the continuous rendering when we closely look at prints (see the 3X and 6X magnifications). The last layer is a gloss coat, supposed to protect photos from abrasions, gas, air, and light. It isn´t perfect though, because pictures can still be scratched.

In the end, 4" x 6" pictures include three superposed layers of cyan, magenta and yellow each with 1772 x 1181 points.

Canon Selphy CP710

Canon Selphy CP710

Canon´s first 4" x 6" printers were thermal. They eventually followed Epson and HP, in releasing an inkjet printer. They finally ended up in a difficult position, having two rival technologies and having to defend both of them. An even more delicate point was the fact that the CD710 uses cheaper consumables, color quality is better, photos are more accurate and sharp, and ergonomics are better. It was hard to stand up for the 810.

Practical and compact, the CP710 isn´t the perfect printer. It includes an LCD color monitor, which is small and immobile. We, of course, prefer bigger movable ones. Also, it isn´t the most gifted with photos, which is a recurrent problem for Canon. Their engineers continue to provide new algorithms that are supposed to give colors that buyers want to see and not necessarily accurate ones, a choice based on consumer opinion. We are surprised by this choice and would like to meet these people. It’s a phenomenon started three years ago. For once, CP710 portraits currently aren´t too red and the dominant color is blue. You can see this in the two color extracts and even more in the black and white photo (X3 magnifying test).

Something new: Canon has integrated a USB cable to connect to your digital camera. This is for PictBridge fans (we prefer using memory card players).

Canon Selphy DS810

Canon Selphy DS810

Canon left the concept of the previous DS700, whose particularity was to be able to connect to a TV via an S-Video cable. This capability is now only available with Sony. Canon came back to a product more in the continuity with other lines with a memory card player and LCD monitor. The only problem is there are a few mistakes. As we said above, a good printer is a simple one. Here there are 15 controls, some of them completely useless, because they are redundant and they can be confused with the others. The printer invites you to click on "SETTINGS" (written on the monitor) but there is no such a control. Either way, in the end it prints pictures that are cut 11% and with a strong dominance in red.

Another big problem and a little like previous versions is that consumable options are more than confusing. For the cartridges it’s simple, you don’t really have the choice as they come in pairs. For the paper it is a little more complicated. The printer is sold with Photo Paper Pro, or PR101 paper, which is a nice gesture as it is their best paper. When it’s finished, our first impulse would be to go out and buy the same, which would be a big mistake. 7,50 € for 20 paper = 37,5 cents per paper equals a total cost per photo of 37.5 (paper) + 19.6 (ink) = 57 cents per photo. Too expensive!
Canon sells two economy packs. The first includes 100 GP401 sheets (190 g/m²) and 2 cartridges for 34.90 €. You will have to buy paper to finish the cartridges, and in the end you will roughly fall under 35 cts per print. The second pack, the GP501, is a whiter and lighter paper (170g/m²) and the result is slightly better. Canon gladly recommends it for photo albums. The price is 9.99€, which equals 30 cts per photo.
In short, this is uselessly complicated. Let´s hope Canon will quickly put some order into this area.

Epson PictureMate 100

Epson PictureMate 100

After creating the concept of 4"x6" printers (the first PictureMate maybe wasn´t the first one but was the most popular), Epson was responsible for its widespread use. Between the first version and this one, the price has been cut in half and a color monitor has been included.

To avoid killing its high-end model, the 500, Epson added several modifications to the 100. First of all the monitor is smaller. Cartridges work with only four basic colors and not six. Finally, ergonomics have been redone. Epson obviously wanted to simplify access to options by making them available on the printer itself. The result is a multiplication of commands and the necessity sometimes to combine them to get the requested option. The result isn´t as good as they hoped for. Only one thing is simple. When the memory card is inserted, you only have to push the central control to launch the printing of all photos. It takes a long time (see printing speed below) but at least it’s easy.

Epson PictureMate 500

Epson PictureMate 500

Epson´s calculation is more or less correct. They eject thin drops, work with 6 basic colors, the cartridge is economical and the LCD monitor big. Add well thought-out ergonomics, ease of use and you have the only inkjet printer that keeps up with thermal printers. The PictureMate 500 also benefits from rather good color quality, that is accurate, vivid and doesn´t denaturize photos. This is something that most competitors are unable to do.

The black and white mode is also more accurate than average. We can see a slight dominance in green, but you have to look hard to see it. This is at least more satisfactory than the PictureMate 100 that tends to be strong in violet.

If there is a downside, it’s slowness. You really shouldn’t be in a hurry.

HP Photosmart 335 and 475

HP Photosmart 335 and 475

One comes with a small capacity cartridge, the 339 (7 ml, for the Photosmart 335), and the other with a big format model (reference 344, 14 ml, with the Photosmart 475). Once this is finished, we advise you to use the same, the 339 cartridge with 100 4" x 6" sheets pack. Everything is the same and the reason why we expected similar results. This was the case except for one detail, colorimetric space. 475 photo prints are a little redder than the 335’s in our opinion.

The good news for the consumer is that the least expensive of the two is the most accurate. This is a meagre compensation, however, considering the two problems we noticed. They are both slow – critically so for the 335 – and ink drops are overly visible. There is so much noise that we can´t see ourselves using them on a daily basis. Especially when we know that other manufacturers sell models that aren’t affected by these drawbacks.

The only advantage of HP over its competitors is that the Photosmart 475 also works in 13 x 18 cm or 5" x 7". This format is much closer to the 4/3 of compact digital cameras. It only truncates half a centimeter in height instead of 1 cm for 4"x6" printers. The paper, however, is more expensive and harder to find. On HP´s website, the cartridge + 60 sheet pack costs 30 euros. The price per photo is 50 cents-only to be used on special occasions.

Lexmark P450

Lexmark P450

Lexmark innovated, invented and releases the first printer with an integrated CD burner. The concept is original. If we give it a little more thought, however, it’s rather useless for the occasional photographer. It is perfect for someone who doesn’t know anything about computers and who stores photos on their computer without saving them, or even worst he who piles up full memory cards. For these people and they exist, Lexmark´s invention is a real blessing. They will be able to make some room on their small hard drives and not fear the next virus. Others will save money. An advanced user will be restricted by the format, since we can now buy 1 GB cards or higher, because of price reductions. A full card won´t fit on a single CD. It doesn´t mean that the idea isn´t good, as it gives something to the average user. The P450 is extremely easy to use. From our point of view, we will wait for the next version and hope that it will be equipped with a DVD burner.

We also hope that this future "P460" (?) will use new cartridges. Even if this is the new generation, print heads eject ink drops that are too large and visible on paper. This is unfortunate because color quality is rather pleasant.

Kodak EasyShare 500

Kodak EasyShare 500

Kodak was the most expensive thermal printer manufacturer in terms of consumables last year. They now have made 180° turn and are the cheapest. From 75 cents per print a year ago they descended to 29 cents. If you often print pictures and are equipped with an older model, you might well save money by throwing it out. Sharpness has also been improved, as well as color quality, but unfortunately not necessarily in a good way. Kodak tried to make the pictures very contrasted and vivid and pushed the gamma a little too far. The result is burned out lighter shades and dark shades that are too deep.

Finally, if the print rate is good and "giant" monitor very appreciable, we feel it’s is a little too noisy. It’s less so than the Sony but more than average.

Olympus P11

Olympus P11

Olympus missed the previous P10 update. They stayed with the bloc concept without a monitor or memory card player even though all of its competition chose to go with that which became immediately indispensable. As we aren´t supporters of PictBridge printing, which often prevents the reading of edited pictures, we tested this model with our computer. In consequence, performance eventually ended up being more modest than expected. We went from an announced autonomous print time of 33 seconds to 50. This isn´t a problem in itself as it’s still the best of all thermal printers.

Photo accuracy, however, is seriously problematic. The P11 systematically zoomed in with the original photos that were reframed under Photoshop to fit 4"x6" paper. It’s the first printer to do this and even with the worst image quality is reduced.

Strike one!

Sagem Photo Easy 260

Sagem Photo Easy 260

Sagem won the 4"x6" printer roundup last year with the previous Photo Easy 255. They accomplished this thanks to the advanced picture editing function, superior sharpness and good color quality. The 260 includes all of these good points with an additional print cost reductions from 49 to 37 cents. Luckily we again find the reframing function, panorama prints, and addition of frames. At the same time, the print rate considerably increased. Photos are now printed in one minute compared to 2 minutes 30 seconds for the previous version. Functioning noise level has also considerably been reduced.

Logically it should win this survey, because all functions have been improved. "All" doesn´t include color quality and Sagem changed it. The 260 colors are darker, too dark. Skin colors lose the natural aspect that they previously had.

A second obstacle to the victory was that Samsung has released a marvellous printer that is almost as fast, cheaper to use, much nicer from the point of view of many users, and is better for color quality...

Samsung SPP-2040

Samsung SPP-2040

Let´s start of by saying that Samsung usually hasn´t had great printers. Their entry level laser printers are of interest, because they are really inexpensive. The others never convinced us and for inkjets it was even more difficult. The multifunction test showed their attempt with printers based on Lexmark core wasn´t conclusive. They have since withdrawn from this market and for this reason we had a little smile when we heard about their entry on the 4"x6" market. We were wrong, however, because the SPP-2040 finally turned out to be a real marvel. It’s fast, cheap to use, its sharpness is one of the best and color accuracy is the best of all. All essential functions of reframing, zoom, and effects are easily accessed.

A few negative points tarnish the perfect picture. There were a couple of errors with edited pictures (incapable of reading them with the memory card player). It also sometimes took very long to display other pictures, and most of all, it’s noisy. This is one point that Samsung really should improve in the future.

Sony Digital Photo Printer FP50

Sony Digital Photo Printer FP50

For those who want to have the entire image chain from Sony, from computer, monitor, to digital camera, here is the indispensable complement. The manufacturer, usually known for its "more expensive than average" products has been reasonable here. The FP50 is in the average price range for buying their product and its subsequent use. It’s the only one that gives the possibility of displaying photos in full screen on a TV. The printer is sold with an S-Video cable and a remote control to navigate between the files and command prints. Because of this function Sony hasn´t included an LCD color monitor, which is unfortunate. Not everybody wants to use their TV. The monochrome LCD monitor only displays a few options such as manual selection of all the pictures at a time, images one by one, or an index.

Finally, the printer works fast and quite well for sharpness and level of detail.

The downside is a much higher functioning noise than average and it’s impossible to directly read/print edited pictures. To print our test photos we often had to work from our computer or else it didn´t work.

Color picture 3X magnified

Color picture 3X magnified

Original image

Original picture 3X magnified	Fujifilmnet photo lab
Canon Selphy CP710	Canon Selphy DS810
Epson PictureMate 100	Epson PictureMate 500
HP Photosmart 335	HP Photosmart 475
Lexmark P450	Kodak EasyShare 500
Olympus P11	Sagem Photo Easy 260
Sony Digital Photo Printer FP50	Samsung SPP-2040

We could take the 20 basic photos tests, the conclusion would always be the same.

Photos precision: sharpness, level of detail

If you look at the extracts above, you can quickly distinguish two categories. There are the inkjet printers on one side and the thermal printers on the other. It’s rather simple, when the level of detail and sharpness is less, it is an inkjet. Only Epson stands out amongst those that use this technology with pictures that are better because they are subtler than the Canon, HP and Lexmark. There is also one thermal printer manufacturer whose photos are very below average, the Olympus P11. This printer doesn´t only truncate 11% of the picture height like all other 4"x6" printers by it also zooms in on pictures. The original photo is only printed at 80% of its length and 72% of height. This is a problem in itself, and made worse by the fact that the printer degrades the original image. We see this with the strong scale effect on the borders.

Inkjet manufacturers defended their products by saying (and they are right) their clients will be happy with their quality. This is true, but you only have to make one simple experiment to realize that it isn´t enough. Give an inkjet print to someone and then the same photo from a thermal printer. He will prefer the second. Now tell them that the two photos cost the same and ask him which printer he will buy.

A second argument for inkjet printers is the magnifying that we made increases the ink drop size. Once more, it is true. The extracts reported above show what a photo "expert" sees, someone who will scrutinize them and look for the tiniest detail. So to avoid being called bad boys, here are two resized extracts to given you the real impression of what you sees with the pictures in hand.

Sony Digital Photo Printer

HP Photosmart 335

The advantage goes to the thermal printers. Also, if you take a close look at the picture or if you have a very good sight, you will see the images as they are reproduced in the top of the page.

Last information, the photo lab print isn´t more precise than the thermal printers. It is even slightly blurred. It is more discreet when you have the picture in hand. This effect could have been voluntarily added to make the prints softer.

Color quality

Both printers can be judged not satisfying on this extract: there is the Canon DS810 that is too red and the Kodak that obviously has some troubles with the gamma.

Compared to the original print, the printers that provide the best results are the Epson PictureMate 500, the two HP, the Lexmark and the Samsung. Except for Samsung, thermal manufacturers have to better adjust their colors. They often print too dark images with too warm colors up to the excess for Sony. It is difficult to believe that it is the same original image when we compared the Sony in one hand and Samsung in the other.

Once more the photo lab doesn´t provide better results than thermal printers: Fujifilm also pushes too much the contrast and red shades.

Black and white picture 3X magnified

Original image

Original picture 3X magnified	Fujifilmnet photo lab
Canon Selphy CP710	Canon Selphy DS810
Epson PictureMate 100	Epson PictureMate 500
HP Photosmart 335	HP Photosmart 475
Lexmark P450	Kodak EasyShare 500
Olympus P11	Sagem Photo Easy 260
Sony Digital Photo Printer FP50	Samsung SPP-2040

Photo precision: sharpness, level of detail

Once again, HP and Lexmark have less precise prints than the others. Even if they also use the inkjet technology, Canon and Epson provide better results. Like the previous test, the Olympus is the only disappointing thermal printer, because resizing degrades the image.

Color quality

Printing black and white pictures in addition to those with cyan, magenta and yellow isn´t that simple. Only a few succeed. Here is the list of the better results: Fuji lab, Epson PictureMate 500, HP Photosmart (both), Kodak EasyShare 500 and Samsung.

Canon (810) and Sagem are too red
Canon, Epson (PM 100), Olympus, Lexmark and Sony are too blue.

Color picture 6X magnified

Color picture 6X magnified

Original image

Original picture 3X magnified	Fujifilmnet photo lab
Canon Selphy CP710	Canon Selphy DS810
Epson PictureMate 100	Epson PictureMate 500
HP Photosmart 335	HP Photosmart 475
Lexmark P450	Kodak EasyShare 500
Olympus P11	Sagem Photo Easy 260
Sony Digital Photo Printer FP50	Samsung SPP-2040

One detail immediately shows differences in sharpness and level of detail. None of the inkjet printers succeed in showing the veins of the eyes. All thermal printers do, even the ones that we appreciate less, because of what they lack in precision or color.

On the original image, the eye is half a cm long.

The most balanced colors are the Fuji lab, Epson, Kodak, Sagem and Samsung’s.

Only one printer was good in all quality tests, the Samsung SPP-2040.

Cost per print

Cost per print

The general rule is:
- inkjet printer photo costs are less than 30 cts per photo.
- thermal printers are above 35 cts per photo

There are some exceptions. The Canon inkjet is lost somewhere in the thermal printer field whereas the Samsung, Kodak and Canon thermal printers have sneaked in with the inkjets.

We noticed that the printer that we appreciated for quality is the most expensive to use (Olympus). The one that we appreciated the most (Samsung) is the cheapest (thanks to a recent 10 € price cut on the 120 paper photo pack). Lexmark, usually amongst the most expensive is reasonable here.

The costs reported above are each time based on the consumable provided, ink + paper sets (except for the Canon DS810 where the two products are sold separately). For the thermal printers the cost can´t be reduced, whereas with inkjets it’s sometimes possible to go beyond the claimed figure. This was the case of the Canon DS810, that printed 65 photos per cartridge instead of the claimed 50, and the Epson PictureMate 500 that printed 192 photos with a single cartridge instead of 135. Actually, the announced capacity is what is guaranteed by the manufacturer and if your pictures are different you can reach higher figures. We printed a series of different pictures, portraits, landscapes, etc. By adjusting the prices of paper packs bought separately, we reduced the cost per photo to 30 cts for the DS810, which joined the inkjet group, and 23 cts for the Epson 500.

This very low cost is a real asset. So with this information why choose an inkjet printer instead of a thermal one? We can now realistically answer that prints are much cheaper for a high level of quality, in detail, sharpness and color.

Speed

Speed

Already before this test some printers were left behind in the race for “best printer”. The HP and Lexmark started with a serious disadvantage due to the accuracy of their prints. With the cost per photo, they had a break, but the speed test takes them directly to the bottom with 2 minutes, sometimes even more per photo! When only one photo is printed, it doesn´t really matter, but with a dozen consequences are much more significant. The wait can be up to 20 minutes when the fastest printers only take 8.

The speed test is the occasion for Canon and Olympus to give great results with the DS810 and P11…two printers that were already eliminated from the race because of the too low print quality.

In this context, Samsung finishes in a very good position. The SPP-2040 isn´t amongst the first three, but the time needed for one print is still acceptable.

One interesting point is a nice improvement in the Sagem printer’s time. The Photo Easy 260 is twice as fast as the previous 255.

Conclusion

Conclusion

For once one product clearly stands out. The winner is the Samsung SPP-2040. We prefer this printer because:
- of the color accuracy,
- the sharpness and level of detail,
- the design,
- ergonomics,
-print speed,
- and the lowest per photo cost.
It makes quite a package!


It’s not perfect. It’s too noisy and doesn´t recognize edited pictures in autonomous mode. The monitor could be bigger, it could be faster and its consumables cheaper. Of course, from our point of view it is the best 4"x6" printer at the moment. Photo labs are much cheaper to use even when including shipping fees-at least in large volume.

For only 10 photos with the possible shipping and other fees the bill is around 4 euros. At 40 cents per print the printers win (if you don´t take into account the buying price). If you take the lowest price on the internet, 150€ approximately, this represents 500 pictures at 29 cents each! Impatience can come with a high price, when we know that photo labs generally take 48 hours.

As for the comparison of thermal versus inkjet technology, our preference clearly goes to the first, even if Epson is the cheapest to use with the PictureMate 500. Thermal sublimation printers are faster overall and their sharpness and level of detail are much better.

We wrote to the inkjet manufacturers, Canon, Epson, HP and Lexmark to simply ask what we could have missed on their models:

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Hello,

We are currently writing an article on 4"x6" printers. It includes inkjet technology and thermal sublimation printers. In the past if there was a difference in price, ergonomics, cost per print this is no longer the case. Most of the products print one picture in one minute and photos cost 29 cts.

Ink drops range from slightly to very visible on inkjet prints. It’s all right if we only have an inkjet photo print in hand but when side by side with a thermal print the ink drops become really visible.

We are short on arguments in favour of inkjet technology for the specific use of photo printing. We would like to give you the opportunity to respond for the sake of our readers in case we missed something. We offer to publish all or an extract of your answer in our article.

Bonus and reoccurring question: Why don´t your printers support 5"x6" format in addition to 4"x6", which would have the advantage of being homogenous to the ratio the digital camera photos?

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Only two manufacturers answered us, Canon and Epson. In short, they say that it is possible to use smaller formats than the 4"x6", and to change the support (mat or glossy). The inkjet has better potential in terms of printing speed (although we saw that thermal printers provided very good results and have evolved very fast). Their last point is that these printers also meet the expectations of those who prefer the quality of current inkjet printers.

Here are their answers (originally in French):

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Canon sells thermal sublimation (Selphy CP-510, CP-710 and CP-600) and inkjet (Selphy DS810) 4" x 6" printers, because both technologies present numerous advantages and are complementary.

The thermal sublimation provides high quality images comparable to the film photos in terms of rendering. It’s possible to handle them immediately without the risk of damage. Canon thermal sublimation printers are very compact and light (800g) and can include an optional battery that makes them completely transportable and autonomous. They don´t really include possibility to edit pictures because their first objective is to be simple and fast to use especially thanks to the Print / Share control ("I connect / I print"). The advantage of thermal sublimation is to guarantee a constant print rate regardless of the subject printed.

In parallel, inkjet technology continuously improves and today reaches a very high quality level that answers to the user expectations. Just like thermal technology, printing formats are multiple (4"x6", personalised format …) but inkjet technology also gives the choice of paper finishing (mat, glossy). The DS810 printer has a very wide LCD monitor of 2.5" that gives a great reading comfort and the possibility to directly choose the parameters from the printer (slide show, contrast, red eye correction). Also, the DS810 has a complete set of inputs: memory card player, USB interface, IrDA and optional Bluetooth compatibility in.

4"x6" thermal and inkjet printing rendering are much different. Some users will prefer the inkjet results and others the thermal…

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It’s true that today thermal sublimation is winning in terms of number of available references on the market compared to the traditional and eternal promoters of inkjet technology, Epson, HP, Canon and Lexmark!

What are the facts in practice? Inkjet technology does more than just resist the ineluctable progression of thermal sublimation. Inkjet sales represent more than 60% of the 4" x 6" market in 2005, whereas the number of references of inkjet products only represents 10 to 15 % of the total amount of available products.

These technologies offer completely similar performances, but with a greater evolution potential for ink jet products (speed, cost…) whose advantages are numerous:
- Exclusive for Epson´s inkjet: proven photo resistance (better than the best rated sublimation models)
- Exclusive for Epson´s inkjet: immediate drying and possibility of manipulation that does not deteriorate the picture.
- Inkjets benefit from more formats available than with sublimation printers (if we don´t mention A0, there is still the 5"x7", A4…)
- with inkjet printers there is a multitude of available papers (from mat to glossy, ordinary 300 g/m² paper…) and without the crenellated or stamp effect easily observable (and without zoom) on sublimation prints.
- optimum colorimetric management with 4 (RGB+ on real black), or 6 colors!
- inkjet printers have a strong potential for evolution. For example we know how to print a 4" x 6" photo in 40 seconds (see our new RX640 that prints 5"x7" in 60 seconds in photo quality) and we keep on improving the speed.

Concerning the "bonus question", the paper format. 4"x6" isn´t the perfect format but rather a step format that will, once the user is reassured on home printing (price/quality at home), it will make it possible to redirect users to other formats and magnification. HP has released a 5"x7" format… Epson and other manufacturers have A4 products (5"x7", 4"x6" in terms of processing capacity) that are as simple to use as our dear 4"x6".

Finally, about the ink drop visibility, they are when we zoom in on pictures. In this case, yes, dots are apparent. But in the real life, users do not compare sublimation prints to inkjet with a magnifying glass. With the naked eye, dots aren´t visible and that corresponds to normal use. The thing is that some manufacturers maybe haven´t reached the same level of quality as Epson…