Thanks Chas, The wood was a couple of logs from a tree we felled last year for my Dad, they were stacked on top of each other in a shed rather than outside, I was a bit surprised that any spalting had happened as I assumed it would need a fair bit of damp, I guess the stacking must have held in the moisture long enough to allow it without overly staining it, a handy way of inducing a better quality of marking if that is how it occurred maybe?