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Mysteries Of The Vortex (Part One)
Mysteries Of The Vortex (Part One)
Author: Martin Reed (Silverprint)
Published by Les McLean
19th November 2008
Default Page 6 - Conclusions - for now...


Conclusion – for now...

Reducing residual thiosulphate levels is the main purpose of print washing and still the leading known predictor of print LE. Many authorities agree that a standard of zero visible staining using full sheet tests of HT-2 is a fully effective practical test for residual thiosulphate levels. See end of article for the formula and testing procedures for using HT-2. The second half of this article “Mysteries of the Vortex Part 2: Archival Washers in Practice” will detail specific tests performed on one make of washer – tests designed not only to prove the effectiveness of the washer, but to support or disprove various ideas and hypothesis about print washing in general. Part 2 will suggest design considerations for a hypothetical “ideal” print washer, and conclude with a number of specific recommendations you should consider adopting in your own darkroom.



Code:
Kodak HT-2 Residual Hypo Test  (Published by David Vestal in 1996)    

  Formula:

      Water               375ml
      Acetic acid 28%     62.5ml
      Silver nitrate      3.75 grams
      Add water to make   500ml

Put 50 to 100 ml of this solution in a small brown glass bottle with a
dropper cap. Keep the rest in a sealed brown glass bottle. Keep it 
cool and in the dark. Don’t touch it or drink it: it’s poisonous and it 
leaves permanent stains.

To use HT-2: Develop and fix an unexposed sheet of the paper you
  are printing on; put it through exactly the same processing as your 
prints, including washing aid treatment and toning. 
  
At timed intervals during the print wash, pull this test sheet out of 
the wash, cut off a small sample, an inch square will do, and put the 
rest of the sheet back in the wash. Blot all surface water drops off 
the emulsion side of the sample with a paper towel, and then put one 
drop of HT-2 solution on it. Leave it for exactly two minutes then rinse 
off the HT-2 drop with cold water, blot the sample with paper towel 
and examine the stain immediately (it will soon darken). 

Do this in dim white light. A definite brown or deep yellow stain shows 
that the wash is far from finished. A light beige stain means you’re 
getting somewhere but have not arrived. When there is no stain at all, 
or a yellow stain so pale that it seems no darker than the paper 
(some papers seem never to get to no stain), the wash is at least fair 
and may be excellent. Then it’s not bad to wash for another half hour 
for luck. The distribution of hypo in the paper can be uneven, so 
although a definite stain always means too much hypo, a very light 
one doesn’t always mean there isn’t too much hypo an inch or two 
away from the test spot. 

If your prints still look new after 200 years, your fixing toning and 
washing were probably good. 

[n.b. a ready-made HT-2 kit comprising solution + colour test-card 
is available from Silverprint]

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  #1  
By Mike O'Pray on 20th November 2008, 12:40 AM
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Many thanks for this Les. Now it's set out and easily accessible.

Mike
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  #2  
By Argentum on 20th November 2008, 10:44 AM
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Thanks for that Les, I've snaffled it and converted into pdf for local reference.
Now if part 2 was only in text format instead of scanned magazine pages I could do the same but with a much smaller file size.
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  #3  
By Ag-Bromide on 21st November 2008, 08:57 PM
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I hope Martin Reed makes it available as a PDF for downloading (unless I`ve missed it on Silverprint`s site).
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  #4  
By Argentum on 21st November 2008, 09:13 PM
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Part 2 is available from the web site but its scanned pages from a magazine which makes it 16MB.

http://www.silverprint.co.uk/pdf.asp

mysteries of the vortex part 2
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  #5  
By Dave miller on 21st November 2008, 09:41 PM
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We will be posting part two here shortly.
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  #6  
By Andrew Bartram on 26th November 2008, 08:56 PM
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What a fantastic resourse this User Group is! I have long mourned the demise of "Darkroom User" Magazine and regularly re-read the original "Silverprint Manual" that went on to be the original AG+ Periodical (now sadly too much devoted to digi stuff I don't want to think about).
Some of the above was indeed published in the Silverprint manual.
Thanks Les for making it available
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  #7  
By Martin Aislabie on 9th December 2008, 01:46 PM
Thumbs up FB Washing Explained

What a well argued piece of work, with some back-up data to support his case.

So often these articles are a mixture of old wives tales and opinioneering.

Thanks for posting it Les

The only thing that puzzles me - why Martin doesn't have this article on his web site along side Part2 ?

Martin
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  #8  
By Les McLean on 9th December 2008, 03:19 PM
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Quote:
Originally Posted by Martin Aislabie View Post
What a well argued piece of work, with some back-up data to support his case.

So often these articles are a mixture of old wives tales and opinioneering.

Thanks for posting it Les

The only thing that puzzles me - why Martin doesn't have this article on his web site along side Part2 ?

Martin
When I spoke to Martin to ask his permission to use the article he asked me to let him have the scans I made from the original publication for he had lost his copy of the first part.
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  #9  
By Dave miller on 9th December 2008, 05:32 PM
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Quote:
Originally Posted by Les McLean View Post
When I spoke to Martin to ask his permission to use the article he asked me to let him have the scans I made from the original publication for he had lost his copy of the first part.
He could just post a link to this site.
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