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Author Topic: Lumachrome process?  (Read 859 times)

Wayne Fox

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Re: Lumachrome process?
« Reply #20 on: January 11, 2019, 05:31:59 PM »

To me it sounds like they are using Pictorico Pro Ultra Premium OHP Transparency Film (or something similar), then laminating that to a ďwhite RC paper baseĒ (basically something like unprinted but processed photo paper. I assume they could use some type of metallic paper for this backer if they want that look). This would make sense if they print the image in reverse then mount the inkjet coating to the paper so the bond to the acrylic is the backside if the film.  One concern I have is the durability of an inkjet receptor coat and ink bonded directly to acrylic, and even though Iíve had great results, there really isnít a good way to test how the bond will hold up. I have several  that are more than 5 years old showing no issues, so it seems the bond is holding up well.

Sounds like a slightly convoluted process for something that is actually much more straight forward (unless for some reason they are bonding that sandwich to the acrylic with Diasec / silicone).  I have face mounted hundreds of prints, both chemical as well as inkjet, and I have seen their prints that are being sold by some photographers in a couple of art festivals I have attended. to me the secret to the final result is simply the fact thatís itís face mounted.  I havenít seen any images they have made that I thought offered anything other than what face mounting other products offer.

But Iíll admit Iíve never compared their process side by side. I can understand their claim that side by side they look better than the fujiFlex versions, but that to me is easily explained in the increased gamut, dmax, and detail resulting from using a high end inkjet printer vs chemical photo paper. But why would this be better than directly mounting a quality inkjet print.
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Dan Berg

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Re: Lumachrome process?
« Reply #21 on: January 11, 2019, 06:23:36 PM »

Thank you Wayne
A great explanation from a very expirenced and valued member.

Ernst Dinkla

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Re: Lumachrome process?
« Reply #22 on: January 12, 2019, 06:22:28 AM »

Actually, the American Institute of conservation has put together a good video on this topic:  https://www.youtube.com/watch?v=bq80xpKzl-w&t=11s

Also, Ernst, matt prints from inkjets are easier to work with when using the Diasec method where as luster or glossy need to be laminated with a film first. Wayne had asked this question in another post a few years ago and never got a response from Miranda Smith, but she explains the process here: https://aiccm.org.au/sites/default/files/SMITHPaper.pdf

[Because you seem familiar with them in the past, why do you suppose they're using a rather gooey silicone process instead of a rolled adhesive?]
I found the patent for Diasec online and along with Ernst's link it explains a lot. I spent a few hours researching yesterday :)

I was not aware of that research. My gut feelings are that Mark McCormick will shoot big holes in the results of the AIC research, especially the fast fading objective of the MFT approach and the limited use of patches (for example a grey area can be a mix of many or very few colorants) and by that not very representative for all the inks used in the print. Little is said about OBA content in papers but the paper area result with Endura will be related to that. Using light without UV does not eliminate the effects of light on OBA content in papers; short term, long term and the dark storage effect. What is shown are mainly dye colorant tests; chromogenic, bleached dye photo papers and dye on inkjet paper.  It will be interesting to see what remaining acetic acid in face mounting does on the long term. Oxidising by gasses like oxygen and ozone may be reduced in face mounting and lamination, the chemistry of the glues and their interaction is not brought to daylight yet. Anyway restoration of any laminated or face mounted print remains an issue how well they stand time.

Getting old, you are right that the lamination is done on the inkjet RC papers before Diasec face mounting and not on the matte papers, used to write that correctly in the past.  BTW interesting that the AIC research mentions that the lamination peels off easier from the chromogenic RC papers than from the RC inkjet papers, the remark that the inkjet has no coating is wrong though. I think it may have more to do with the age of the laminated prints.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots

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Ernst Dinkla

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Re: Lumachrome process?
« Reply #23 on: January 12, 2019, 06:41:59 AM »

To me it sounds like they are using Pictorico Pro Ultra Premium OHP Transparency Film (or something similar), then laminating that to a ďwhite RC paper baseĒ (basically something like unprinted but processed photo paper. I assume they could use some type of metallic paper for this backer if they want that look). This would make sense if they print the image in reverse then mount the inkjet coating to the paper so the bond to the acrylic is the backside if the film.  One concern I have is the durability of an inkjet receptor coat and ink bonded directly to acrylic, and even though Iíve had great results, there really isnít a good way to test how the bond will hold up. I have several  that are more than 5 years old showing no issues, so it seems the bond is holding up well.

Sounds like a slightly convoluted process for something that is actually much more straight forward (unless for some reason they are bonding that sandwich to the acrylic with Diasec / silicone).  I have face mounted hundreds of prints, both chemical as well as inkjet, and I have seen their prints that are being sold by some photographers in a couple of art festivals I have attended. to me the secret to the final result is simply the fact thatís itís face mounted.  I havenít seen any images they have made that I thought offered anything other than what face mounting other products offer.

But Iíll admit Iíve never compared their process side by side. I can understand their claim that side by side they look better than the fujiFlex versions, but that to me is easily explained in the increased gamut, dmax, and detail resulting from using a high end inkjet printer vs chemical photo paper. But why would this be better than directly mounting a quality inkjet print.

I miss the Iridium particles part in your explanation. There will not be any Iridium in that sandwich (way too expensive) but I think they refer to mica nano particles covered with a metal or dye to yield a pearlescent effect. Often the names of that kind of pigments refer to iridium that can have that effect too.

An inkjet paper that is named like that;
https://www.rauch-papiere.de/en/products/photography-and-fineart/mediajetr-photographersline/mediajetr-sip-260-silver-iridium-pearl/

So  one of the papers like that but face mounted as I mentioned in the first reply in this thread.

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
March 2017 update, 750+ inkjet media white spectral plots
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Wayne Fox

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Re: Lumachrome process?
« Reply #24 on: January 12, 2019, 11:31:19 PM »

I miss the Iridium particles part in your explanation. There will not be any Iridium in that sandwich (way too expensive) but I think they refer to mica nano particles covered with a metal or dye to yield a pearlescent effect. O
Yeah, sort of marketing speak (like the whole process) my best guess is whatever ďiridiumĒ there  is in the RC paper base that they are using. 
« Last Edit: January 13, 2019, 02:07:48 PM by Wayne Fox »
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mearussi

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Re: Lumachrome process?
« Reply #25 on: January 13, 2019, 10:02:45 AM »

According to their web site it seems like nothing more than transparency film laminated to acrylic in the front and a white base on the back, similar to printing on glass with a backing.

http://www.nevadaartprinters.com/fujiflex-acrylic-photo-prints

Given this, how then is their process different from just printing on white film with face mounted acrylic?
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