[alt-photo] Linen Paper for Iron-based Processes

[Mike Ware]

A New Linen Paper for Siderotype (Iron-based) Processes

As  fellow-practitioners of the "ferric processes" will know only too  
well, the last technical difficulty confronting us is the uncertain  
quality and composition of the paper stock that we coat.
Everything else lies within our control.
In recent times, I've heard that the commercial supplies of cotton  
furnishings for high quality papermaking have become increasingly  
unreliable, sometimes causing problems in the changing  
characteristics and supply of some of our most popular papers for  
hand-coating, such as Arches Platine and Bergger COT 320.

For nearly 20 years I've successfully used a 100% cotton handmade  
paper called 'Buxton' paper, from Ruscombe Mill at Margaux, the  
background is here:

http://www.mikeware.co.uk/mikeware/Alternative_Printing.html

Recently I've been testing a new paper from Ruscombe Mill, which will  
become fully available by the end of April, this year. The launch of  
this product has been announced on the Mill's website:

http://www.ruscombepaper.com/

It will differ from all other alternative process papers in being  
handmade from 100% linen cellulose fibre (i.e. made entirely from the  
best quality flax, not cotton).
Chris Bingham, the master papermaker at Ruscombe Mill, is making this  
product for the alternative process community, and has named it  
'Herschel' paper, remembering that great man's innovation of the  
siderotype processes. He sees it as the future replacement for Buxton  
and Talbot papers.

I've tested Herschel paper with argyrotype, new cyanotype,  
palladiotype, platinotype, platino-palladiotype, and new chrysotype.  
It performs superbly with all these processes as I practice them.

I guess that the different performance of flax versus cotton  
cellulose lies in the fibre morphology constraining the image  
substance. The structure of the flax fibre may enhance its ability to  
retain nanoparticles of image pigment, which is essential to the  
success of all siderotype processes. During the wet processing, I  
don't see any "bleeding" of image substance - even Prussian blue,  
which is notorious. I've been particularly delighted with the colour  
of the silver images it yields with my argyrotype process, and the  
range of colours obtainable with new chrysotype, which are also  
highly dependent on particle size.

Herschel paper, like Buxton, is 'engine-sized' with neutral  
alkylketene dimer, AKD. It can be rod-coated with sensitizer solution  
similarly to Buxton, with the addition of Tween 20 surfactant to the  
sensitizer, to ca. 0.1-0.2%. There is, of course, absolutely no added  
chalk or other alkaline buffer in this paper, which seriously inhibit  
siderotype, no surface sizing such as gelatin, which 'kills'  
platinum, nor clay or gypsum fillers, OBAs, etc., etc. With all  
processes, the Dmax is high, the cold-pressed surface is perfectly  
matte with a 'fine tooth' texture, the clearing of whites in the wet  
processing is rapid and complete, and the gradation and smoothness of  
the image tones are excellent. This linen paper sheet has much  
greater resilience and wet strength than cotton papers,  
notwithstanding its moderate weight of 200 gsm. Dimensional stability  
is good, with about  ±1% hydroexpansivity; but to obtain a perfectly  
flat sheet after processing, it does need to be dried slowly under  
pressure.

'Herschel' paper will prove an excellent replacement for Buxton, with  
the advantage that the Mill's supply of linen cellulose fibre (from  
flax grown in Northern France or Belgium) is more reliable and  
consistent than present supplies of cotton. In high quality  
papermaking, confidence in the raw materials is paramount. One need  
have little worry about archivality, because linen was the first  
plant fibre historically available to Europeans for making fabrics.  
Long before the growth of the cotton textile industry towards the end  
of the 18th Century, linen rags were being processed in the 15th  
Century for European papermaking, and such papers have endured well  
to this day. I believe that linen has also been used for banknotes,  
bonds, and other security papers.

I apologise if you encounter multiple postings of this information,  
(and I beg the usual critics kindly to note that I have no commercial  
or pecuniary interest in this product.)

With good wishes to all,

Mike

Dr Mike Ware
mike at mikeware.co.uk
http://www.mikeware.co.uk