Originally Posted by Zephyr
I use three strands of embrodery thread and then I tie a square knot plus one extra knot for good measure. I tie mine on top and try to have the knots blend in with the quilt colors. I only leave the tails about a half inch or so long.
Mine are 1/2" or so, too. A good knot is the "surgeon's knot" where you wrap the left thread over the right TWICE. That keeps it from loosening while you do the right over left.