Re: Gum woes

Hi Scott,

Finding papers that I like for gum printing over the years has often been
frustrating ­ there are many papers that I have used but no longer do as
they just don¹t give the results I want. Hence the recommendation of
Fabriano. Christina¹s is right about sizing too ­ I can¹t comment on the
chrome alum as I have always used formalin. I changed my sizing routine
following an online class with Steven Livick some years back and use just
one coat of a 3% solution of gelatin with 20ml formalin per 1 litre of
gelatin. I suspect however that with some papers a second coat may be
necessary.

I find that a good test for paper for gum printing is to see what happens in
the pre-shrink stage in hot water ­ if the paper buckles and becomes soft it
probably won¹t work that well. Keep an eye on the Arches BTW, the last time
I tried it the paper buckled significantly in the pre-shrinking stage.

Regards

Hamish Stewart Gum Bichromate Photographer - http://www.gumphoto.co.uk

On 9/5/05 03:09, "Scott Wainer" <swphoto@verizon.net> wrote:

> Hi Hamish,
>
> Changing the gum/pigment/dichromate ratio helped but the emulsion still seemed
> to separate when applied to the paper. I just finished up my stack of gelatin
> sized Lenox and wanted to see if the paper was part of the problem so I took a
> piece of unsized Lenox and coated it with an emulsion of 1g pigment per 20ml
> gum mixed 1+1 with dichromate. The paper just soaked it up - taking almost 6ml
> emulsion for an area a little bigger than 5x7. With a 2 minute exposure and a
> 60 minute still water bath all I got was a red square and no image - talk
> about staining. So the Lenox is now reserved for other processes. But I did
> notice that the emulsion did not separate so maybe it was the size after all.
> Digging around in my paper pile I found 25 sheets of Fabriano Uno and 25
> sheets of Arches Aquarelle (both 140lb hot press) which i'll try this week. I
> also found some Coventry Rag and Strathmore Drawing Bristol which I might try
> but the Coventry looks to be just as thirsty as unsized Lenox and I doubt the
> Strathmore will hold up under the required soaking. I'll have to get some
> Artistico and give that a try too, in addition to other colors.
>
> Regards, Scott
>
> swphoto@verizon.net
>
>
>
>> ----- Original Message -----
>> From: Hamish Stewart <mailto:hamish.stewart@gumphoto.demon.co.uk>
>> To: Alt Photo List <mailto:alt-photo-process-l@sask.usask.ca>
>> Sent: Sunday, May 08, 2005 7:35 PM
>> Subject: Re: Gum woes
>>
>> Scott,
>>
>> I don’t want to repeat too much of what has already been said but a few
>> quick points
>>
>> I have always found that a simple ratio of 1:1 of the gum+pigment and the
>> dichromate works just fine – I have never added any additional water at all.
>> On occasion I might increase the ratio of the dichromate. I have used both
>> ammonium and potassium - what works best will depend on your lights and your
>> negatives.
>>
>> Your pigment load seems high to me - I tend to work with between 1-3g tube
>> pigments to 12ml gum. Stronger pigment load will give you more intense colour
>> but will increase the potential for pigment staining
>>
>> I am not familiar with the paper you are using – Kerik’s suggestion of
>> Fabriano Artisco is a good one – I have used this for quite a few years and
>> the hot pressed surface works very well with gum
>>
>> You might also want to use some different tube colours – I recall that
>> windsor & newton colours - windsor blue, alzarian crimson and cadmium yellow
>> all worked well for me in the past.
>>
>> Best of luck with three colour printing!
>>
>> Regards
>>
>>
>>
>>
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>

Hamish Stewart Gum Bichromate Photographer - http://www.gumphoto.co.uk
Received on Tue May 10 02:21:41 2005