I personally would find some thread that either 1 matched the material or 2 variagated or metallic something to add a different look to. Then you could use one color for the top and one for the bottom.

Start with using the right size needle: Topstitch #80/12 or #70/10 are good with invisible thread. Start with your top tension at .5 and adjust up as needed no more then 3.5 . Use a thin cotton or poly bobbin thread size 60 or more. The spool should unwind in the vertical position. Nylon transparent thread is not good for quilting, it turns brittle over time. Poly transparent thread is what you want to use.
Also if your thread is labeled polyamide, that is not polyester, it's nylon.

Everything worth knowing about thread is on Superior Threads website.

I have used it in the needle and the bobbin, but I prefer to use regular thread in the bobbin. When doing so, you almost always need to LOWER the top tension.

I've used that stuff a few times. Sometimes it works great, sometimes it's a nightmare. I have to reduce the tension to 1-2. Not always, but is usually works better if the thread is brand new -- if it sits on the shelf for a while it tends to break when used. Also wind the bobbin slowly.

Thanks for all of the great responses. I think I will try one more time using some of your suggestions, if that still doesn’t work I will go back to cotton. Thanks again for all of your help.

I've used it in both when I've done placemats, tablerunners and small landscape wallhangings.