it has been suggested that wetting agents help in the spreading of platinum/
palladium.
It does not seem to help all that much in prints above 16 x 12 where
humidification does the job better. It has also been suggested that the effect
of emulsification is more significant as it controls the depth of sink into the
paper.
As to EDTA I have never had any problems with degradation of the highlights but
I am concerned as to its long term effectiveness as after ten years or less the
iron seems to reappear. PM suggests that that is because the reaction between
the EDTA and the ions it is chelating is in equilibrium.
Are there chelating agents where this would not be the case ?
Terry King