Invisible thread is nothing like the old "fishing line" of day's past. A quality well made invisible thread is super fine and very supple. There is still a school of thought that nylon will turn brittle with age and use but I have found nothing to confirm that is the case with today's monofiliment threads. Unfortunately the brands I use and am familiar with you will not find at any big box store. You will have to order on line or find a quilt shop that carries them. But JoAnnes should carry something.
Superior threads monofiliment is "Monopoly" and unlike most monofiliments on the market, Monopoly is a polyester.
YLI makes a nice one called Wonder Invisible
Sew Art makes one that gets great reviews but I have never tried it
Finally Filtec (the makers of Glide thread) make a nylon one called Essence.
Here is a nice review I just found comparing several brands. Two that I have mentioned are included (Sew Art and YLI)
https://www.quiltersreview.com/six-i...t-to-the-test/