Digital BW, The Print

Joost,
 
> I'd rather stick as close as possible to your formulation. That allows much better sharing of experience. A logical approach would then be to put in 1/3 of the Photo-flo 600 and add extra glycol.
...


Photo Flo and other consumer products use propylene glycol (http://en.wikipedia.org/wiki/Propylene_glycol).  It's safe, but probably not as effective for some uses as some of the others. 

(I'm not interested in unsafe chemicals at all.  My chemist brother died at 59 due to chemical exposure.) 

I bought a gallon of propylene glycol and tested lots of different concentrations of it.  Photo Flo uses 25 - 30% propylene glycol, and with a 10% Photo Flo base mix, that amount of glycol seems to work well.  Note that Epson cleaning solution is about 45% glycol.  It makes a good cleaner, but the higher percentages of it make printing rougher.  When I dropped it too low, however, the latest C6 mix clouded, which has correlated with less than perfect printing in the past.  So, I'm not sure what the optimum percentage is, but the 25-30% in a 10% Photo Flo 200 base seems to do the job, and it avoids people (where PF 200 is available) from having to buy another chemical.

Paul
www.PaulRoark.com