1 Attachment(s)
Canson Platine - edges discoloring
Attachment 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.
Re: Canson Platine - edges discoloring
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?
Re: Canson Platine - edges discoloring
Quote:
Originally Posted by
rjphil
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/l...es-and-privacy
Re: Canson Platine - edges discoloring
Quote:
Originally Posted by
rjphil
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.
Re: Canson Platine - edges discoloring
Quote:
Originally Posted by
rjphil
Attachment 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.
Re: Canson Platine - edges discoloring
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.
Re: Canson Platine - edges discoloring
Quote:
Originally Posted by
Vaughn
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.
Re: Canson Platine - edges discoloring
Whoops! The "Platine" threw me...I was thinking digital neg, too.
Re: Canson Platine - edges discoloring
Or did you mean Arches Platine?
Re: Canson Platine - edges discoloring
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 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