Re: tonal inversion and pigment loads

Okay, so when I was waiting for my guests this afternoon, I mixed up
some lamp black and ran a test strip, trying to re-create the
inversion, but I didn't get the mix pigmented enough, and there was
no inversion, just a light stain. In other words, it was just a
normal test strip that was lightly stained with a light grey stain
from the end of the normally toned steps to the end, and in the
letters in the top that should be white. So, to my mind, just a
normal print, stained. But guess what, the numbers 18 through 21
have flaked off.

So I'm just curious; would you guys call this an inversion? I
wouldn't call it an inversion until the stain is dark enough for the
missing numbers to show up white against it.

http://www.pacifier.com/~kthayer/html/missingnumbers.html
Katharine

On Jan 27, 2006, at 1:37 PM, Katharine Thayer wrote:

>
> On Jan 27, 2006, at 12:14 PM, Jack Brubaker wrote:
>
>
>> Katherine wrote:
>>
>>
>>
>>> so on all the steps from 10 on, all the gum emulsion would wash off
>>> the steps entirely except for the numbers,
>>>
>>>
>>
>> Perhaps this is evidence for the static charge being involved. It
>> might be
>> that the charge holding the pigment in a surrounding area (when
>> encircling
>> an area like the numbers) overwhelms the the static charge in that
>> area and
>> eliminates or reverses the charge.
>>
>
> Umm, maybe I'm not following you here, but this doesn't make a lot
> of sense to me. So let me rephrase to see if we're understanding
> each other. The conditions in steps 10 through 21 (first strip)
> should be the same; the question is, why did the numbers wash off
> only in steps 17 through 21? The numbers should consist of
> hardened gum of the same density from steps 1 through 21. The
> stain is the same tone from steps 10 to 21, meaning there's no more
> hardened gum underneath to act as a resist against the stain, as
> there is in steps 5 through 8, and so the unhardened gum should
> dissolve equally and completely from all the steps from 10 to 21.
> Your explanation above is intriguing, but I don't think it takes
> these facts into account.
> Katharine
>
>
>
>
Received on Fri Jan 27 22:30:03 2006