Graham I was looking to source extra fine copper wire to tie some PTN's using Davy McPhail's method. I finally located the right stuff at Maplins (After receiving advice on this forum).It was 50SWG (standard wire gauge) It came on a spool containing 2000 metres? and cost about 8 quid.You transfer it onto an empty spool (you can use a leccy drill if you want) Use a ceramic bobbin holder and you are sorted.Enouhg for 2 lifetimes tying and not costing 4 quid plus for 50 yards!