Hopefully this will help other buyers. I followed the instructions and every time the knot would lock solid when you are meant to pull it down to the bead. I found one or two videos on the internet well worth looking at as they are easier to follow than the instructions and confirmed that I was following the instructions right. Looking at the silk thread Griffin, also bought from Cookson and after much head scratching, I tied the knot the opposite way around to the instructions. It then slips down to the bead using a firm force. So, if you have the same issue, just reverse the instructions for forming the knot. 2 stars for the instructions, 4 stars for the product. I have found that it makes knots nice and tight to smaller beads, but I cant get it to form knots that tight to large beads.I hope that helps someone