I have the Janome and I use 2.0 for piecing and 1.8 for strip piecing. This is my first time working with 100% aurifil cotton thread and I am worried about the life of the thread. I have always used a blend thread. I buy alot of vintage thread, and 100% cotton thread loses it tinsle strength as it ages. I will be long gone when the aurifil thread ages, but It still is one of my concerns.