Hi guys, I am currently using a Copper plating solution (Water, Copper Sulphate, Sulphuric Acid, NaCl and CUbath copper brightener) on gold seed layer. I try to keep the plating rate to 30mA / cm2. I have noticed sometimes that the copper plated on the seed surface is not bright enough and it gets a pink colour. Do you have any idea what the reason for that might be? Nik Dee