View Full Version : Canson Platine - edges discoloring
196654
This Platine print was hot mounted on rag board with acid free tissue, but the edges are discoloring. I have one other print doing the same thing. Only these 2 prints were hot mounted, I usually use corners. Tried to send a message to Canson with no response and cannot find a contact phone number for them. Also checked with the maker of the tissue and they are stumped as well. Does anyone know the upper temp limit for hot mounting these papers? I typically use 185F. Thank you.
Peter De Smidt
18-Oct-2019, 07:28
The paper doesn't have optical brighteners, right? There's so many variations of papers, that's it's hard to be sure. How were they mounted in the press? Release paper? Mat board?
Oren Grad
18-Oct-2019, 08:20
Tried to send a message to Canson with no response and cannot find a contact phone number for them.
How's your French?
Canson - Canson-Infinity.com
RCS CANSON SAS : 335 620 241
N°67 rue Louis et Laurent Seguin - CS 70139 - 07104 Annonay Cedex - France
Phone : 04 75 69 88 00
https://www.canson-infinity.com/en/legal-notices-and-privacy
Pere Casals
18-Oct-2019, 08:34
196654 but the edges are discoloring.
There is a way to check if OBAs are present. Take an UV torch ($10, amazon)...
...and in darkness see if the paper is fluorescent. If you are not used to check that then use a paper sample known to not contain OBAs and another sampe known to contain it, to learn to see the difference, which is quite evident anyway in new papers, but more difficult to see when the OBAs are faded by aging.
The other suspect is acid, even very small amounts of acid in cardboard may turn prints yellow, the process is faster if also OBAs are there.
Overtemperature when pressing is a contributiong factor, as (my guess) with overheating acid flyes from any place to the wrong place. 185F should be OK , I'd use this: https://www.drytac.com/product/flobondcarrierfree/ 175-200°F (79-93°C). Anyway, if it's true Canson, migration of acid to the surface should be the reason, the question is how acid ended there.
Many times exposing these yellowed prints to direct sunlight may totally remove the yellowing. I'd try that, also you may use an UV flood to do it indoors. You may place the UV torch on a corner for a week to see if it works.
interneg
18-Oct-2019, 08:35
196654
This Platine print was hot mounted on rag board with acid free tissue, but the edges are discoloring. I have one other print doing the same thing. Only these 2 prints were hot mounted, I usually use corners. Tried to send a message to Canson with no response and cannot find a contact phone number for them. Also checked with the maker of the tissue and they are stumped as well. Does anyone know the upper temp limit for hot mounting these papers? I typically use 185F. Thank you.
Two major questions: what was your dwell time; and is the board buffered or unbuffered?
The paper is OBA free as far as I know, but may have incorporated pigments or similar to whiten it.
I would say incomplete clearing. The chemicals entered into the paper deeper thru the cut edges and thus not did not clear as fast as the rest of the paper.
Solutions: Less time in chemicals, longer clearing, or cut off edges after processing and drying.
paulbarden
18-Oct-2019, 08:54
I would say incomplete clearing. The chemicals entered into the paper deeper thru the cut edges and thus not did not clear as fast as the rest of the paper.
Solutions: Less time in chemicals, longer clearing, or cut off edges after processing and drying.
Vaughn, it is my understanding that this print is on Canson Platine, which is an inkjet paper, not silver gelatin. Admittedly this problem does resemble what you describe.
Whoops! The "Platine" threw me...I was thinking digital neg, too.
Philippe Grunchec
18-Oct-2019, 13:56
Or did you mean Arches Platine?
Ken Lee
18-Oct-2019, 14:54
Hi RJ -
My experience is limited but I've never encountered any recommendations for hot-mounting inkjet prints.
Are the paper base, inkjet receptor coating, inks, pigments, gloss agents and binders designed for heating ?
I print on Canson Platine Fibre Rag (https://www.canson-infinity.com/en/products/platine-fibre-rag) regularly (no OBA's, 100% rag) but I never permanently fasten prints to a backing board. No adhesives of any kind: just framing corners, archival back and overmat. The mat is over-sized to give a 3/8 reveal all around, so you see the original paper and composition but the image is held flat. Because Platine is heavy there's little worry about curling. With a mat over the print there is no contact between the glass and the image.
- Ken
Sal Santamaura
18-Oct-2019, 16:54
...I never permanently fasten prints to a backing board. No adhesives of any kind: just framing corners, archival back and overmat. The mat is over-sized to give a 3/8 reveal all around, so you see the original paper and composition...
Neutrals are tricky. I've evaluated a number of inkjet papers for that configuration and found only one combination where the 3/8-inch white reveal is compatible with the overmat. Granted, I haven't tried every paper or mat board, but if one sticks to majors like Rising / Bainbridge AlphaRag and is sensitive to the subtle variations of "white," this will be challenging. :)
Ken Lee
18-Oct-2019, 20:33
Framing and matting is a matter of taste and can make or break a photo.
There has to be a harmony between the frame, the mat, the print paper color and the print ink color - which lifts the photo to an even higher level of refinement or emphasis.
It's one thing to save pennies and present all our photos with a uniform treatment (as in a gallery setting), but to avoid a sterile urban museum look and for the best individual rendering of each photo I go to the frame shop and explore the many options until one best combination emerges. One image at a time.
Often the framer (or my wife) are much better at bringing out the full potential of images because they are not attached to our limited conceptions.
https://www.designsinkart.com/library/M-AbridgedHistoryofDryMounting200410.htm
https://www.designsinkart.com/library/A-MysteryOfDryMountAdhesives199809.htm
https://www.framedestination.com/framing-accessories/photo-mounting-supplies/mounting-and-laminating-handbook-by-chris-paschke.html
Check out the mounting information Chris Paschke has. She would be a good person to check with as her knowledge of the problems and solutions may be helpful.
This is the Canson Platine for inkjet printing.
Pere Casals
20-Oct-2019, 06:56
This is the Canson Platine for inkjet printing.
Time ago we were requested by a photolab that was moving to the ink to find a method to detect OBAs, we found that a simple UV torch test proved to be conclusive. Then we were asked to find acidity, we made several tests...
We found that an easy way was wetting the paper/cardboard a bit and then throwing a tinny drop of pH test reagent, of narrow detection range that should be very sensitive with low acidity.
The water used to wet the paper should be bidistilled and just boiled to expel any diluted CO2, water used should be 7.0pH checked, as CO2 in the ambient disolves in the water to end in 5.9pH
From those tests we learned that acidity may make its path into a paper through humidity, as CO2 in the ambient is diluted. The chemist that was explaning that to us to also told that this is well known, karstic formations (caves) were made in that way, CO2 in the rain drops makes water acidic and this is what disolves limestone. What is clear is that long term moisture is a main factor in the paper yellowing...
Anyway there are standards for procedures in determining acidity in the paper, an specialized lab would say it better.
_____
It would be interesting to check what acidity has that yellowed paper, and what is in the not hot mounted papers... it is extrange that only those that were hot mounted had the problem...
I think that this is an interesting case, please report what happened if you can find it, it would be a good teaching.
How's your French?
Canson - Canson-Infinity.com
RCS CANSON SAS : 335 620 241
N°67 rue Louis et Laurent Seguin - CS 70139 - 07104 Annonay Cedex - France
Phone : 04 75 69 88 00
https://www.canson-infinity.com/en/legal-notices-and-privacy
My French is "tres mal..."
Sorry - started a response yesterday and the site went down for maintenance. Pending contact with Canson (and going forward anyway), I am going to only use corners for mounting. Thanks everyone for your input.
Two major questions: what was your dwell time; and is the board buffered or unbuffered?
The paper is OBA free as far as I know, but may have incorporated pigments or similar to whiten it.
If you mean my mounting time in the press, it is 2 minutes @ 185F. I'm not sure if the board is buffered or not.
I have not heard back from Canson after several tries. Does anyone have a US contact phone number ? Thanks !
I don't have a contact number for Canson but you might want to ask the Piezography guys.
They know all about papers, manufacturers, etc. and have been consistently helpful and generous. They might also have useful contact info.
See https://shop.inkjetmall.com/
https://www.lodima.org/advances-in-archival-mounting-and-storage
An older article from noted LF photographer Michael A. Smith that may be useful.
Maybe try mounting some on the Artcare Alpharag board and doing a test to see how it works?
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.