Thanks for all the advice. Have given up on the phthalocyanine, but recently did a pit firing using copper sulphate (dissolved in pool acid!) and got some interesting results. So I will keep experimenting.
Thanks Peter for your response. I did a test firing today and guess what- it burnt off as you said- completely bleached result.Oh well, I tried. I suspect this is the stuff they use in washing powder called "blue" or something like that- makes your whites whiter. Anyway I am still curious as to see what it does if I combine it with other oxides- grind it with say, iron oxide. It must be very volatile and if I could find a way of removing the water from the molecule other than using heat?? any chemists out there who can advise? Or just stick with good old cobalt!