I have used cone thread for piecing a lot in my life. However, most of mine has gotten pretty old. Since I started quilting on the long arm quilter, I have become somewhat a "Thread snob". I will only use bottom line in my bobbin, and when I quilt I use a great poly or cotton top thread. Now piecing, I normally use a good cotton thread from Connecting Threads but in a pinch, I wouldn't think twice using my old serger thread.