NCC Streetscape supply GFTK vdw 840 Plus polymeric sand based jointing mortars for domestic patios and paving for joints 3mm - 30mm wide
It is available in stone grey or basalt what is darker and nearer to black
NCC Streetscape Limited
Hope this helps
Driveways Patio's and Paving Specialists
Thanks for the replies. Looks like the NCC stuff will be our option.
I even got thinking about using sbr and cement dye! Admitidly that Idea wasn't about long!