I've never tied a quilt, but Hospice gave my dad a tied cheater cloth quilt and as he died of Alzheimers, he loved to feel the knots within the quilt. So tied quilts will always have a special place for me. Sorry to interrupt this thread with emotions, but I was moved

Embroidery thread

I always use six strands of embroidery floss tied in a surgeons knot.

I use yarn as I have a bunch of it and it has always served me well. :-D

I use Perle Cotton thread, variegated (the pale colors), thread through needle, pull two strands through and tie. It ties tight, doesn't come loose like yarn - did that once, washed it and the knots came apart (double knots besides)! So it is Perle Cotton Thread. Works like a charm! Edie

Funny you should ask...I just tied a quilt! I 'googled' it, and found many of the same answers you are getting here. I used embroidery thread (because of the color selection) and used the 'surgeons knot'. When all I did was tie quilts I used a square knot, and sometimes they would loosen. I also put a tiny drop of Fray Check on each knot in hopes they will stay put! Good luck...

I used Perle cotton and the 'surgeon' knot on two quilts for my granddaughters. They have been used hard and laundered many times and remain tight.

I still have the first quilt I made and it is tied with yarn. he quit is falling apart from age and use but the yarn is in great shape.

I tie all my quilts here..as I like the feel much better then the others for sleeping under. I have always used yarn as my grandma did. The quilts I have that she has made for me, the one is 40 years old and the yarn is still there (the yarn is lasting much longer then the fabric is). So now the quilt is on display only..not to be used on the beds.

I usually use crochet cotton.