Yes Anie, Sodium Chloroplatinate is used to increase contrast in the print. Since is forms part of the image instead of restraining the reducing accion it gives better results than using the evil #2 solution, but be very careful, the platinate is very powerful, most people dilute it to 10% and even 5% at 20% I would not reccomed it for an 8x10 print, 1 drop will probably cause too much contrast. BTW if you use platinate as contrast control, you will have to increase your printing times.

The one you want to make coating solution is Potassium Chloropaltinite.