[alt-photo] Re: pigment problem

Julian Smart juliansmart at virginmedia.com
Thu Feb 10 21:03:19 GMT 2011

Hi Cor,

Thanks for the interest.

There is a full and relatively detailed version of my Gum printing workflow 
and methods on my website which should answer most of your questions. 
www.artofsmart.co.uk under "The Techy Bit"

For those questions not answered on the site:

I pre-shrink twice.

The paper is mostly flat, though one corner does tend to curl quite 
markedly. Funnily it's always the same corner....

The formaldehyde is neat - don't know the exact concentration but I bought a 
5L bottle 12 years ago and still have over 3L left. I'm worried about it 
oxidising (I understand it turns into Formic Acid) so will soon decant it 
into 500ml bottles for better storage. Since I stopped tray hardening I 
reckon I have enough formaldehyde left for the next 250 years-give or take!

My 100ml of gelatine will comfortably cover 2 76x56 cm sheets (whole 
imperial). I tear down two sheets into roughly A3+ sized sheets as this is 
the largest size my printer and bath will accommodate.

Hope this helps,


> Thanks for sharing your method, Julian
> I have got a few questions;
> I assume you pre-shrink the paper first? What is your method?
> Is the paper flat enough after the pre-shrink and size, I mean flat
> enough for a gum coat?
> What concentration of Formaldehyde do you use?
> Approx. how much paper surface can you size with that 100ml gelatin?
> Thanks,
> Cor

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