I've used serger thread for years, but I only use MaxiLock. There is some type of code as to the quality and I can't remember what it is, but MaxiLock has the right code. I've used serger thread in my LAM for years and never had a problem. My fav is the variegated colors. Olivia's Mommy has washed her quilts many, many time and has had no problem with them falling apart. I always use serger thread in my FW bc it's so easy to clean.