Always, the final choice is yours!
As a norm the industry and home sewers now use Trilobal Polyester threads, the colour is vibrant, colourfast and strong and performs flawlessly in the fastest of machines and it is robust enough for the daily rigours of work wear.
Rayon/Viscose is made from cellulose and is traditionally the embroiderer's favourite, it has a beautiful lustre, is softer thread and is always reliable to give beautiful results on delicate fabrics.
If the project wants a more subtle look, we suggest an Aurifil 40wt for 'open designs' or the 50wt for a more dense design.