I use old thread all the time and it seems OK. After reading this thread I will check it's strength the next time. I have had no problems. I have collected it from thrift stores and garage sales. I have a large variety of colors and have them in small baskets by colors that are simalar. Then I put the smaller baskets in a large basket and stack the baskets on top of each other. I cover the large basket with a cloth so the dust stays out.