Re: Gum hardening: top down?

Jack,
It's just regular mylar, scuffed lightly with 320 grit sandpaper on
the printing side to give it some tooth for the hardened gum to
attach to.
Katharine

On Apr 10, 2006, at 2:00 PM, Jack Brubaker wrote:

> Katherine,
>
> Was the image you printed on mylar on the frosted mylar? Did you do
> anything
> else to prepare the mylar for the gum? Any sub coating?
>
> Jack
>
>
>> From: Katharine Thayer <kthayer@pacifier.com>
>> Reply-To: alt-photo-process-l@usask.ca
>> Date: Mon, 10 Apr 2006 12:26:57 -0700
>> To: alt-photo-process-l@usask.ca
>> Subject: Re: Gum hardening: top down?
>>
>> P.S. I kind of like the melting softness that's achieved by printing
>> through the back of the mylar.
>> kt
>>
>>
>> On Apr 10, 2006, at 11:33 AM, Katharine Thayer wrote:
>>
>>
>>> Okay, I've coated a very thick, very heavily-pigmented gum emulsion
>>> on mylar and printed it from the front and from the back. A couple
>>> of comments before I give you the URL:
>>>
>>> (1) though the emulsion was very heavily pigmented, two things
>>> resulted in not a very deep DMax: (a) the fact that I used ivory
>>> black, a transparent pigment (if I were to do it again, I'd use
>>> lamp black) and (b) the fact that it's printed on a transparent
>>> material and was scanned as a transparency, with the light shining
>>> through it. But the thing to note is, be that as it may, the DMax
>>> is about the same in both prints.
>>>
>>> (2) there's a light brown pigment stain (ivory black is a brownish
>>> black) in both prints that is probably a function of the heavy
>>> pigmentation. It hardly shows in the prints themselves, but for
>>> some reason was accentuated in the scanning.
>>>
>>> (3) I don't honestly know what to make of the results. If you look
>>> just at the prints on mylar, you'd have to conclude that back-
>>> printing is much superior to front-printing, at least for a thick
>>> coat on mylar. But if you compare the back-printed print on mylar
>>> to the regular front-printed gum print (using a less heavily-
>>> pigmented emulsion) on paper (at the bottom of the page), it's hard
>>> to claim that the back-printed print is superior. But since they
>>> are on different materials, it's apples and oranges.
>>>
>>> So I guess if I were forced to draw a conclusion from this rather
>>> inconclusive test, I'd say that if you are going to print on mylar
>>> using a very thick and heavily pigmented emulsion, then you'll
>>> probably do better printing from the back. But if you're printing
>>> on paper, you can get fine results printing from the front with a
>>> less pigmented emulsion.
>>>
>>> http://www.pacifier.com/~kthayer/html/topdown.html
>>>
>>> Katharine
>>>
>>>
>>>
>>
>>
>>
>>
>
>
Received on Mon Apr 10 16:35:19 2006