Re: shrinking Masa
I have shrunk Masa as described on Sept 4 for 1.5, 3 and 4.5 hours.
These were coated with the traditional 2A + 1B emulsion, exposed, developed, dried and checked vs. the neg for shrinkage.
Whereas the 1.5 h-soaked paper showed a uniform shrinkage of ~1mm all around, the 3 and 4.5 h soaked sheets shrank slightly more, providing for improved registration. I consider this acceptable unless further experience is contraindicative.
I gelatin sized all of these, dried, then flattened them and found that the shrinkage described above still held. I will do gum passes on these aligning the neg as closely as I can to the centre of the image (which is quite intricate).
I have also heard from 3M and they suggest that 3M Photo Mount (no catalog number specified) is the most appropriate product to get Masa to adhere to Yupo. They recommend evaluating it by applying to one surface (normal method) and, if necessary, on two surfaces. A two surface bond will be like a contact adhesive - no repositionability. They do not have data to state how well it will work in different moisture and/or chemical environments.
I think I will stay with the shrinking protocol and forget about mounting Masa on Yupo. This seems to work in my hands.
I hope this helps. Rajul
On 5-Sep-07, at 11:30 PM, Loris Medici wrote:
Hi Rajul, what happened? Did you get milder / no registration problems or are you completely free of them? BTW, the tests / prints I shared before were all made on pre-shrinked paper. I was still getting to much size variation / no perfect registration. I don't soak Masa paper more than 5-10 minutes since it's so thin and gets thorougly wet in just few moments. My understanding of shrinking is to let the paper absorb as much water as it can (in other words saturate it) and then dry it. I don't think that any paper would benefit a soak more than 30 minutes unless it's extremely heavy (such as > 282lbs / 600gsm) and / or is heavily sized. BTW, I don't understand why people pre-shrink in hot water and/or for hours -> that would be harmful to the original sizing!? Of course I may be completely wrong here -> I'm sure someone will correct me and/or explain why they're doing so... Regards, Loris. -----Original Message----- From: Rajul [mailto:email@example.com] Sent: Tuesday, September 04, 2007 10:16 PM To: firstname.lastname@example.org Subject: shrinking Masa Hi all, As a way to address the registration problem with the above paper, and an attempt to bypass the Yupo - 3M adhesive solution, I shrank Masa in room temp water, mat face up after wetting both sides. A 90 min shrinking was reasonably effective and did not abrade the surface. A 12 hour shrinking was detrimental to its integrity and coated unevenly with the cyano emulsion. I will shrink for longer than 90 min to see if it will permit even more accurate registration and report. Incidentally, 3M have responded to my request to help me with the most appropriate product to use for affixing Masa to Yupo by asking me for more detailed info. I am hoping that I do not have to go the Yupo route, though it was a good thought! Rajul