Both threads have their place in embroidery, but they differ in key ways:
Trilobal polyester (like our Elite thread) is colorfast and won't fade, strong and durable for everyday use, washable without bleeding or weakening, and lint-free for clean machine operation.
Rayon (like our Pearl Crown Rayon) has a softer, more subtle sheen, drapes beautifully for decorative work, is ideal for special occasion garments, and is best for projects that won't be washed frequently.
For quilts, children's clothing, and everyday items, we recommend trilobal polyester for its durability. For heirloom pieces and special occasion garments, rayon offers a classic, elegant look.