I use Madeira Rayon most of the time. I have tried to use polyester (my Janome came with some poly threads) but I never got to like them. The rayon is softer. On my Bernina I have to lower the tension to 2 if I don't want to break the thread, but then it is problem free. It is so strange to me, when people say rayon is not colorfast. One of the first embroideries I made was a rose on viscose jersey. It has been washed over and over and I can't see any difference in the embroidery, but the blouse is nearly worn out after five years.
So go for what you really like.

thanks for the answers, now i feel smarter

People buy polyester thread because it won't bleach out. But the rayons are beautiful and I buy them too. I often mix the poly and the rayon threads in the same design if I need a color that I have in one and not the other. Don't buy too much thread of any one brand at first. Sometimes machines don't like a certain brand of thread and act up which often ends up in thread breaks or other problems. I have a Bernina and the Isacord is the most trouble free thread on my machine, but you have to buy a 1000m spool of it. So if I only need a small amount of thread for a design, I buy other brands that have smaller spools. Combining ME and quilting is fun to do. I especially like it in doing crazy quilting.

Becky, polyester simply refers to the kind of fiber the thread is made of. On the other hand, Madeira is a brand name of thread--Madeira sells both polyester as well as rayon threads for machine embroidery. If you are starting out with machine embroidery and since you have a Bernina 580, you might want to start with a few reels of Isacord polyester thread, if it is available to you since Isacord is associated with Bernina, has a nice sheen, at least here in the United States it is pretty cost-effective and you will get some practice at using your embroidery module with a thread that is known to work well with Bernina machines. Once you get comfortable with machine embroidery, then you can vary your brand of thread and perhaps even play with the more expensive threads. Personally, I like to use Superior Bottom line in the bobbin for machine embroidery, but people do use Isacord as the upper thread as well as in the bobbin with success. Have fun with your embroidery module!

hi all,
i am new to machine embroidery, i have B580 from not long ago.
i have small question -
does any body can enplane the difference between polyester thread and madira?
what is the best for having a good results?
the price difference is huge! so i need to know, before i will start.
thanks guys.
becky:)