As a rule, dyes that have good UV fade resistance have inversely bad ozone fade resistance

[mikling]

Coincidentally as pharmacist was doing his testing on lightfast inks, I was also on a similar mission to offer superior inks more closely matching Epson Claria. I had dropped hints of what was forthcoming in past threads.

In discussion with an ink chemist and a very good one at that, this is what I learned.

First overall aspect that needs to be understood is this.

As a rule, dyes that have good UV fade resistance have inversely bad ozone fade resistance. If you don’t use paper with a coating that swells around the ink droplet to protect it from air, dyes that might be very lightfast will fade very quickly due to ozone.

So in general very lightfast inks do not perform well in ozone resistance. Why this upside down relationship, you ask?

Here's the reason why.

Color is due to conjugated double bonds in a dye molecule. When the bonds are broken, color is reduced.

Dyes that are good for UV light fastness generally have a metal atom like copper complexed into the dye molecule. When a photon ( UV) breaks a bond ( the bond is made by shared electrons between two carbon atoms), the metal atom limits the damage because metal atoms are electron rich and donate electrons to the bond.

Ozone breaks a bond due to oxidation. The electrons in the metal atom in a lightfast dye actually help promote the oxidation and destruction of the double bond, in layman’s terms.

Apparently Epson's competitor had once forgotten this relationship. Unfortunately Pharmacists test did not include or exclude the ozone content or determined how much was present.

With that in mind, I ended up getting something that is promised to be balanced in most aspects.

It is said, there's no free lunch. Maybe it is true that you can't get something for nothing.

Don't ask me to explain further because I won't be able to very well, I am not an ink chemist by trade. These will be soon available after profiles are developed...just waiting to be scanned and put through the computer......not that profiles are really necessary for most with this inkset. Really.

 

[turbguy]

When you say "ozone", do you mean O superscrict 3? Or "other" airborne pollutants, that are reported as "ozone" in US weather reports?

 

[pharmacist]

Hi Michael,

thanks for the information. I was wondering if it would be possible to make a two component dye ink for a printer like the Epson R1800 or Canon Pro-10 with the gloss optimizer filled with something I would call a polymerisation layer, that covers the printed area completely, so the dye inks start a polymerisation reaction, that create a very firm and stable bound that will seal the dye molecules. So the ink can be formulated with a polymerisation initiator and the gloss optimizer does the polymerisation, but is only triggered when mixed with the ink (containing the polymerisation starter). So in this case, as dye ink does not need gloss optimizer at all, the gloss optimizer cartridge is used as a sealing ink cartridge.

 

[pharmacist]

I am thinking about Mikling's problem of the oxidation of the metal ions in those fade resistant dyes. I could be dramatically reduced by using anti-oxidants that capture the ozone and other oxidative gasses and act like reducers. Now the problem with most anti-oxidants tends to change colour when being oxidised by the oxidative gasses and when all have been used, they will start to the next best thing and those are the metal ions in these dyes. It only slows down the oxidation process of the dye molecules, but it does not stop it.

 

[mikling]

With dye ink, don't forget the porosity of the paper from the rear. Ten years ago, we had a multitude of papers that would have been ideal...swellable that would have done more than what pharmacist is proposing ( I think) as it would actually dissolve into the gelatinous layer and totally surround the dye molecules. Even without super lightfast inks, swellable papers do an excellent job at extending the life of prints made with normal dye ink. No extra coatings would have been necessary. Unfortunately these type of papers were misunderstood and coupled with the rise of pigment inks, hardly any remain in the market, if any. Just to cite an example I picked up many many years ago a large stash of these in the 13x19 sizes , HP Premium Plus, at the flea market going for a pittance. I think the last holdouts were Ilford Galerie CLASSIC line and the HP type from a few years back. Occasionally, you'll see these papers appear on Ebay possibly sourced from a clearout surplus situation.

The weakest point with these papers is that they are NOT waterproof at all.

Ozone: http://en.wikipedia.org/wiki/Ozone

One thing that comes up with the two part mix is that dye ink will dive beneath the RC layer and the polymerisation layer will stay on top thus missing the dye below....and the porosity issue as well. Also with the gloss optimizer, its performance will vary by paper; larger pored coated papers will have different looks as compared to tighter pored coats because the penetration of the optimizer varies. Unless you incorporate a driver that allows variation of the optimize density on the fly.

 

[Łukasz]

Hi Michael,

thanks for the information. I was wondering if it would be possible to make a two component dye ink for a printer like the Epson R1800 or Canon Pro-10 with the gloss optimizer filled with something I would call a polymerisation layer, that covers the printed area completely, so the dye inks start a polymerisation reaction, that create a very firm and stable bound that will seal the dye molecules. So the ink can be formulated with a polymerisation initiator and the gloss optimizer does the polymerisation, but is only triggered when mixed with the ink (containing the polymerisation starter). So in this case, as dye ink does not need gloss optimizer at all, the gloss optimizer cartridge is used as a sealing ink cartridge.

There is a need for a dedicated purging pad to avoid polymerization on printhead surface.
Or just another printer for coating only...

Ł.

 

[pharmacist]

Hi Lukasz,

I didn't have thought about that problem....hmmmm it would certainly clog the purging pad . It will desastrous...

 

[Łukasz]

In most cheaper Pixma printers, PGBK printhead is separated from CLI printhead and have their own purge pad and outlet to absorber. But PGBK is limited to print bordered and constrained with CLI-BK print, thus some hack have to be done in printer driver.
Hacking printer driver should be sufficient to allow coating from PGBK printhead over borderless A4 prints.

Ł.

 

[pharmacist]

One could use formaldehyde to revive the colours in a faded dye ink print. Not ideal, as it is quite toxic .

 

[The Hat]

One could use formaldehyde to revive the colours in a faded dye ink print. Not ideal, as it is quite toxic .

The use of that stuff I reckon would being the average printer to a full Dead stop,but your colours would still look great in 100 years..