How to make a bracelet as exclusive and cute as Lola Rose jewellery?

I am in my late teens, and I have a thing for jewellery! Presently I am struggling to find the right sort of cord for making a bracelet. I have always liked Lola Rose jewellery and I actually want to make myself a bracelet like the ones by them, where they are bead threaded but have a sliding knot. The beads are threaded onto a fairly thick cord (looks like nylon) and the sliding knot is tied with the same stuff. I can't seem to find a cord like this anywhere I have found thread which is far too thin and rattail which is far too thick to go through the beads. I would be really grateful if somebody could help me in making my bracelet as exclusive yet cute as Lola Rose! Can anyone please help?