I always buy green\brown\blue sleeving on a roll as the random coils get in a bit of a state. Niglon I think it is that some of it is, the others are random makes on unlabelled drums IIRC.
You could always buy some random style sleeving and stick it on an old 4mm earth drum.
You could always buy some random style sleeving and stick it on an old 4mm earth drum.