Re: Boiling gelatin

Ryuji, there's nothing in that earlier quote that contradicts what I'm
saying today. I said there that my experience has been that a hot
gelatin size can result in sizing failure that creates speckles in the
print. I said then that I don't know WHY that is, only that I have seen
that it is so. I also said then that it may be true only with certain
papers or certain hardeners. I now realize that it probably has nothing
to do with the gelatin at all; if I had suspected before that it had
something to do with the gelatin, that would have been a mistake. But I
was very careful to say even then that I didn't know what the cause was,
so it's not like I was ever claiming anything definite about the
gelatin. You may have me mixed up with someone else.
Katharine Thayer

Ryuji Suzuki wrote:
>
> From: Katharine Thayer <kthayer@pacifier.com>
> Subject: Re: Boiling gelatin
> Date: Sat, 12 Mar 2005 07:41:50 +0000
>
> > As I said, I don't think it has anything
> > to do with gelatin, much less with boiling gelatin; that was a red
> > herring that was raised to a huge issue by non gum printers who rudely
> > barged into a discussion of this topic.
>
> That's a really lame excuse. See below. It is too soon to quibble
> around only after a month of posting pages of your opinion. Now all of
> sudden your mistake (if you admit so, though I doubt it) is someone
> else's red herring. What a nonesense. Where is your science?
>
> After all, if what you said last month was really based on reliable
> and repeatable data you collected with confidence, you would not get
> frightened by one person coming up with merely one more piece of data,
> just because it is completely contradictory to your experience. If
> your previous post was really based on facts and hard evidences, you
> would not forget your belief so quickly and now make up a new story
> that is completely inconsistent with your own old story.
>
> --
> Ryuji Suzuki
> "Well, believing is all right, just don't let the wrong people know
> what it's all about." (Bob Dylan, Need a Woman, 1982)
>
> From: Katharine Thayer <kthayer@pacifier.com>
> Subject: Re: Autoclaving gum and gelatin
> Date: Tue, 08 Feb 2005 10:18:07 +0000
>
> > I thought we had settled this the last time around, but I'll review for
> > clarity what I thought was decided: Kate, Judy, I and perhaps others,
> > all reported that we have observed that if the gelatin gets "too hot"
> > then it doesn't work well as a size for gum. I don't know the cutoff
> > temperature between "too hot" and "not too hot" but I just heat the
> > gelatin enough to dissolve completely and to stay melted while brushing
> > on, which doesn't have to be over 120F, and it works fine. If it does
> > get too hot, it results in a characteristic speckling pattern, as Judy
> > said, and as I and others have also observed. My information comes not
> > from old literature, which I don't read and didn't know that it said
> > anything about this, but from my own experience.
> >
> > In that earlier thread, I said "I'm not sure it matters what happens
> > technically to the gelatin; what is important is that overheating the
> > gelatin seems to lead to imperfect sizing, for whatever reason." I
> > still stand by that statement. But I'm not arguing that the gelatin
> > loses its ability to gel, or that it otherwise "breaks down," only that
> > something happens to its ability to provide an adequate size for gum. I
> > won't say what that is, because I don't know, but it doesn't really
> > matter what causes it physically or chemically, the fact is that this is
> > what happens, at least in my shop. But what the heck, the guy should
> > just autoclave his gelatin and try using it for a sizing for gum, and
> > see what happens; the more information the better.
> >
> > As I said, it's been my observation that when the gelatin is overheated,
> > the sizing fails and results in speckling. That observation isn't
> > altered by all the arguing and bloviating about gelatin and its
> > different states and the ability to make calves foot jelly by boiling
> > calves feet. All those things are no doubt true, but still, if you get
> > the gelatin too hot, the resulting size will give you speckling in your
> > gum print. At least that's what I've observed a couple of times, and I
> > found that lowering the temperature of the gelatin took care of the
> > problem. In social science research we call this a single-subject ABAB
> > research design; it is a good design for a situation like we've got in
> > gum printing where the "tests" that are done can only be done one gum
> > printer at a time. If you see a particular result under one condition,
> > and you don't see the result without the condition, and if this pattern
> > is repeated, where every time you see the result, the condition is
> > present, and when you remove the condition the result goes away, it's
> > fair to assume that you've learned something.
> >
> > For both Judy and myself, it looks like we've learned that for our own
> > case, it was the heat that made the speckling. But whether this only
> > applies to glyoxal-hardened and unhardened gelatin, or only in our own
> > particular labs, one can't say, and I don't think either of us are
> > saying. What I've said is that this is my experience, use it if it's
> > useful to you. But to hoot the observations out of existence simply
> > because they are inconsistent with some theory of how gelatin behaves,
> > is itself inconsistent with being a scientist. Scientists rely on
> > observations; if the observations don't agree with the theory, they
> > adjust the theory to reflect the reality of the observations, rather
> > than dismissing the observations out of hand. When at least three people
> > have observed that hotter gelatin results in sizing failure for gum, and
> > that using a lower temperature eliminates the speckling, then it seems
> > outrageous to me to be so derisive about those observations.
Received on Sat Mar 12 10:47:42 2005