Look At These!!!
 

I have never seen spools of thread this large before. These came from an estate sale. I got 4 spools of which the two largest ones are white for about $1.50 each. I also got some embroidery thread for tying quilts and a ruler that I do not even know how to use. I am hoping I can use this thread in my sewing machine without any trouble. I think these large spools are usually for sergers.

wonderful find, I wouldn't have passed that up, even it I have more embroidery thread than need.

I assume as you do that they are for a serger. If yous DSM isn't picky with thread, then go for it. My Bernina doesn't like anything but Mettler silk wrapped thread.

You will LOVE the Olfa Lip Ruler!!! When you line up the ruler, you catch the lip on the edge of your cutting mat. It helps to keep it from slipping. There are a couple of videos showing how to use it if you can't figure it out. I have a couple of different sizes and love them.

Thread may not be serger...I have large spools like that for my L/A. Look inside the cone might be a label there....

I've seen those used with industrial machines as well. Just might need to check the thread weight. Otherwise, as mentioned previously, if your machine isn't a thread snob, put them on a thread stand and go for it!

If it's spun polyester thread, it's the cheapest and not very nice thread you can get(I'm trying to be nice). It's made to be used in many layers-like 4 or 5 threads on a serger to be strong enough for use. I would be very careful how you use it as serger thread is not a good thread for piecing or quilting because it's weak. Hopefully it's not a spun poly.

I have cotton threads on cones like those. The serger thread cones are normally fatter at the bottom and taper in as it goes to the top. Also, most serger thread is not a consistent weight. Pull a few inches off and you can tell if it is serger thread by the thinness then fatness of the thread.

A way that I try to check & see if it is polyester is to pull it and try to break it. Most polyester thread I have seen takes longer to break than the cotton. It also melts easier.

Great find. Those spools of thread look very interesting! I would definitely experiment with them and see how you like them.

The spools look like the spools used in a sewing plant. Usually the thread is high quality so it won't break or fray causing downtime. Sew a seam and if your machine likes it and you can't rip the seam easily then it's good to go.