This is a very strong button twine and can be used as an alternative to linen twine for fixing buttons. Be careful though because unlike its linen counterpart the knots can work loose. Sold by the 10 metre piece or the 1/2 kilo ball.
NB for example to order 20 m put 2 in the qualtiy box and choose the 10m price from the grid.
Why not order a buttoning needle with 10 metres of buttoning twine?