RE: shrinking Masa
Hi Rajul, Since I currently print small (around 16 x 24cm, 6 5/16 x 9 7/16") and my subject matter is often very detailed and textured, even the slightest registration problem is disappointing to me. If I were printing large (>= 30 x 40cm / 11 13/16 x 15 12/16" that is) that wouldn't bother me at all, but it does now... Maybe I should leave back my urge for detail and sharpness when doing gums - but I'm not ready to give up yet. I apply the adhesive only to Yupo by means of two perpendicular coats. I tape Yupo to a larger scrap sheet tacked to the wall, spray, quickly untape it and put it down onto Masa laying on its front (back surface looking up - I lower Yupo onto Masa a la Albumen, by bending it) and press it with my palm (starting from the middle, towards the edges and corners). The whole operation (including taping) does not take more than 30 - 45 seconds. I use the paper the next day. If Yupo is too costly you can do it on alternative substrate such as Mylar. (Maybe that would be better, since UV won't reflect back from the base; I had to cut exposure by 1/3 stop, for paper affixed to Yupo...) Good luck! Loris. -----Original Message----- From: Rajul [mailto:eyeear@telus.net] Sent: Thursday, September 06, 2007 7:34 PM To: alt-photo-process-l@usask.ca Subject: Re: shrinking Masa Hi Loris, 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
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