It’s no secret that I am attracted to shiny objects (you should see my jewelry collection!). So of course, I want my quilts and embroidery projects to be just as shiny. I’ve been sewing with Fantastico and Magnifco to get my high-sheen fix, and thought I’d explain the science behind why some polyester threads have a high sheen and others don’t.
Smooth fibers such as silk, multi-filament polyester and rayon tend to have a higher sheen than non-smooth fibers (such as cotton and spun polyester). However, even within this smooth fiber category, there is a wide range of sheen or luster. High sheen is the result of each individual micro-strand (sewing threads are made up of many micro strands) reflecting light, and the shape of the individual fibers determine how light is reflected.
Think back to 9th grade science class. We know that we aren’t really seeing objects with our eyes. We see the light reflected off the object, passing through the optic nerve, into our brain. Light or the absence of light has everything to do with how we see things, including whether an object is shiny or matte.
Round fibers - Regular multi-filament polyester threads such as So Fine! #50, So Fine! #40, and Bottom Line are examples of multi-filament polyester threads. Filament means a continuous strand and multi means many. The threads are made of many long, continuous strands of polyester which are twisted together to create the finished thread we sew with. Each micro strand which makes the thread is round. Light reflects off these small, round fibers in a way which makes the thread appear as medium sheen.
Trilobal fibers - Magnifico, Rainbows, Nature Colors, Living Colors, and Art Studio Colors are examples of Trilobal Polyester threads. Trilobal fibers have three distinct sides ('tri' = three and 'lobal' = sides), so when light hits them, they reflect back the light in a direct path, resulting in a high-sheen appearance. Although the individual micro-fibers are triangular in shape, when multiple strands are twisted together to make the final thread, the end result is a smooth, round, high-sheen thread. Until recently, trilobal polyester fibers were weaker than regular round polyester fibers, so we had to choose between strength and high sheen. But no more! Our high-strength, high-sheen trilobal polyester threads, Magnifico and Fantastico are created using new high-tenacity (high-strength) trilobal polyester fibers. Both of these thread lines consist of 192 micro-strands of high-tenacity trilobal polyester fibers twisted into a smooth, round #40 thread.
Irregular fibers - Most rayon threads are irregular. We don’t use or recommend rayon threads because they’re not universally colorfast and tend to be weaker than polyester threads.
Voila. Here is our threaducation for today and I am happy as a clam stitching with my beautiful high-sheen thread. To see more beautiful work done with our high-sheen trilobal polyester threads, please visit a previous blog post by Hollis Chatelain.