Re: gloy for tricolor on yupo?

On Apr 1, 2006, at 9:02 AM, Katharine Thayer wrote:

>
> On Mar 31, 2006, at 11:02 AM, TERRYAKING@aol.com wrote:
>
>
>>
>> In a message dated 31/3/06 7:30:43 pm, kthayer@pacifier.com writes:
>>
>>
>>
>>> I just don't have any
>>> more patience with all this guessing and supposing about how gloy
>>> "should" work better than gum to print on these surfaces, simply
>>> because it's more "gluey" in quality.
>>>
>>
>>
>> .
>>
>> Perhaps a more appropriate analogy would be that of the duck.
>>
>> If it looks like a duck.,quacks like a duck and walks like a duck,
>> it probably is a duck.
>>
>> Gloy and gum look and behave in much the same way.
>>
>
> Well, this is certainly my experience, although I only had about 5
> ml of it to test; it seemed in appearance and in its printing
> characteristics to look and behave very much the same way. But in
> that case the argument that it "should" behave differently on hard
> surfaces than gum seems harder to justify. In any case, as I keep
> saying, I'm withholding judgment til someone actually reports
> actual experience with this, maybe even shows us some prints.
>
> But to suggest that if gloy acts like gum, quacks like gum, and
> walks like gum it probably is gum, is of course a nonsensical
> statement. Gloy may behave like gum, but gloy is not gum. Let's
> not get carried away with our analogies.

My point here, lest it be missed, is that the two aren't the same
substance. They may behave and look and print and feel the same way
(and BTW, I didn't find the gloy more "gluey" in feel or in coating
properties than gum; it really did feel like the same thing) but gloy
is PVA, a very simple and well-understood polymer, mixed with some
other stuff, while gum arabic is an extremely complex arabinogalactan
protein, with an enormous, not entirely understood and somewhat
indefinite structure. Gloy and gum arabic may behave the same,
and the crosslinking mechanism may well be the same (although this is
only a hypothesis) but they are quite different substances in
chemical and physical structure, was my point.
Katharine
Received on Sun Apr 2 10:01:40 2006