suitably complexed cupric solutions can deposit conductive copper films electrolessly on properly catalyzed non - conductive substrates , at plating bath ph values in the range of about 2 . 0 to 3 . 5 , using a non - formaldehyde reducer such as hypophosphite . certain conditions are critical to successful results : ability of the complexer selected to chelate copper at ph values of 2 . 0 to 3 . 5 at elevated temperatures ; avoidance of certain anions , such as halides and acetates , in significant concentrations in the plating solution ; and provision of an &# 34 ; active &# 34 ; catalytic surface on the non - conductive substrate .