Using a different yarn for a pattern
I want to make a pattern which is in Hayfield Soft TWist and needs 7 balls and replace with Sirdar No 1 DK.
Tension wise they are the same - but soft twist has 325m per ball and the No 1 has only 230m per ball.
Am I right in thinking that I will need 10 balls and not 7?
ie 325 x 7 = 2275m divide by 230 = 10 ?