mrred
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In addition one is restricted to using amines for pH control.
This is not a big restriction, as the DEA/TEA/Ascorbate mixture ratio can be freely chosen to get the pH and buffering you want. With Propylene Glycol as solvent you can achieve the same with Metaborate, Borax and Boric/Ascorbic Acid.
Is there any data about long term stability of this HQ stain?anyone that claims that hydroquinone produces less of a stain that catechol hasn't really done the testing imo.
sounds expensivewith that amount of HQ:confused:I have used the following with success:
50g HQ
4g Metol
4g Ascorbic Acid
1000ml Glycol
as a 'B' 200g/L Sodium Carbonate (mono)
mix 1:1:100 for times start w/pyrocat times, since it is based on that formula. I get a nice red-brown stain
If you mix the A part in TEA, will the ph be high enough?
i have used hydroquinone and metol as a staining developer and it stains very well - by very well i mean that the stain contributes substantially to the printing process. the formula is similar to pyrocat hd but it does require some adjustment and testing to obtain a favourable outcome.
sol a,
metol 1.8g
hydroquinone 4g
sodium metaborate 1g
water 100ml
use 5ml in 500ml.
the alkaline bath is sod. carbonate 2.5g / 500ml (any more and fog/stain increases unecessarily)
the above is the result of about 2 months of testing and printing/living with the prints.
at the end i felt that the image quality was a bit 'synthetic' and 'plasticky' - the stain is very prominent - more prominent than catechol.
anyone that claims that hydroquinone produces less of a stain that catechol hasn't really done the testing imo.
the above formula Works without the metol (i've tested it). the metol contributes to the final image quality. you would have to experiment with it yourself to arrive at your own, aesthetically informed conclusions.
sounds expensivewith that amount of HQ:confused:
Is there any data about long term stability of this HQ stain?
anyone that claims that hydroquinone produces less of a stain that catechol
Interesting. IIRC either Mason or Glafkides mention that the stain is less. In addition I have never encountered a staining developer based on hydroquinone and I have dozens of formulas.
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