U of S | Mailing List Archive | alt-photo-process-l | RE: shrinking Masa

RE: shrinking Masa

Hi Alberto,

Original sizing holding the fibers makes sense, thanks much!

But if original sizing is already holding them in the same position
relative to other fibers, why bother with them? Don't we just need cold
(room temp.) water take care of those which are not so tightly bound to
go on? That would be my take...

You're right about gum stretching the paper further more; when I look at
the back of print I made on 300gsm Artistico (pretty strong paper!) in
oblique light, I can clearly define the black borders and densest part
of the image as protrusions - this definitely shows that gum stretches
paper even more after it's dry... What I was surprised about is the fact
that you can't see this relief effect on the image side, it's just on
the back side (unlike carbon prints). The only effect you see on the
image side is the gloss in the shadows...


-----Original Message-----
From: Alberto Novo [mailto:alt_list@albertonovo.it] 
Sent: Thursday, September 06, 2007 12:24 PM
To: alt-photo-process-L@usask.ca
Subject: Re: shrinking Masa


I won't enter in the Masa problem, but simply give my opinion on
I compare the shrinking of the paper to what may happen with new cloths.
fact, shirts, socks, sheets, curtains, etc. are used to become shorter
the first washing if this has not been performed by the manufacturer. In

this way, also the paper, made from a wet process but almost ever 
calendered, needs to be wetted again to allow its fibers to find their
position. If this is performed in warm water the sizing does not hold
fibers any more, and so it is more effective. The drawback is that the 
sizing is damaged and you need to size again.
However, I believe that the gum layer itself contributes to shrink the 
paper, making this problem not ever (or not fully) dependent on the 
pre-srinking and unsolvable if not glueing the paper to a rigid support.
drawing lines near the sides of a pre-shrinked paper, cover only one
with gum+dichromate, expose, develop and dry, then measure the distances

between the parallel lines comparing the zones with and without the gum