Fused a simple flower to try out the threads. The pink and green are the Rayon threads and the center of the flower is buttonhole stitched with YLI 100 wt. Silk.
I was really surprised at how much more bulky the Rayon thread looked compared to the silk. Not sure yet how I feel about that but it will definitely be a consideration when stitching. The photo below is of the new flower and the tulip applique done all with the silk thread. (Don't pay attention to the stem of the tulip as it is the trial block where I determined it was too skinny.)
I am really leaning towards the silk but finding a supply of thread with lots of colors to choose from is a problem. Most quilt shops around here only have just a few basic colors of the silk so may end up ordering on line. I am a hands on person and like to hold fabrics and threads together to see the true colors so prefer to not have to order online. If there are any Nebraska or Kansas quilters reading this blog that know of a shop that carries a lot of different colors of YLI silk thread please let me know.