Digital BW, The Print

Seth Rossman <seth@...> wrote:
>
> ... question about the Edwal LFN.  It just seems to 
> me that the components are in Paul's formula, and the 
> addition of such a (relatively) minute amount serves little purpose.

Often the use of even less than 1% of one of these strong surfactants is optimal.  Edwal LFN really helps the blend.  I based much of what I  recommended on actual tests of different amounts -- examining high resolution scans of test prints.  I don't claim that 1% is perfect and 1.1% too much, 0.9% too little.  But as I moved up in larger increments, the increment I tested above 1% (I forget the exact number) resulted in no improvement.  

The same type of progression was used with Photo Flo.  The 10% amount for that looks much larger, but look at how little active surfactant is in that mix.

I did also round to easy-mixing numbers.  Very slight differences make little of no visible differences. 

We will have to keep an eye on the performance of these inks as the printers get faster.  The rheology may become more critical, and the surfactant mix is a very significant part of the overall formula.  I make no claims that the ones I specify are the ultimate; they work and are readily available.

Paul
www.PaulRoark.com