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Fiber Shapes and Light Reflection | Why Trilobal Threads are Shiny

Posted: 1 August 2013 at 6 a.m.

The Main 3 shapes of Fibers

Most of the threads we use are round and smooth, as a result of twisting multiple strands together.  We often think of thread consisting of only two or three strands (2-ply or 3-ply) twisted together.  In the case of spun threads such as cotton or spun poly, it may be that simple, but with multi-filament threads such as polyester, silk, or rayon, it gets a little more complicated.  A #50/3-ply polyester thread such as So Fine! #50 has three strands twisted together, but each of those three strands or plies are made up of many micro-strands twisted together. Less expensive threads may have a low number of micro-strands. High quality threads have as many as 48 micro-strands in a single ply. 

Smooth fibers such as silk, multi-filament polyester, and rayon have a higher sheen than non-smooth fibers (such as cotton and spun polyester). However, even within the smooth fiber category, there is a wide range of sheen or luster. High sheen is the result of each individual micro-strand of fiber reflecting light, and the shape of the individual fibers determine how light is reflected. 

Round fibers   Regular multi-filament polyester threads such as So Fine! #50, Lava, and Bottom Line fit into this category.  As light hits the fibers, it is reflected away from our eyes, which results in a medium sheen appearance. 

Trilobal fibers  Magnifico, Rainbows, Nature Colors, Living Colors, and Art Studio Colors threads are made from trilobal polyester fibers.  Silk is a natural trilobal fiber.  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, giving a high-sheen appearance.  Although the individual micro-fibers are trilobal 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.  We now have both.  A new high strength, high sheen trilobal polyester (Magnifico) is now available. It consists of 192 micro-strands of high tenacity (strength) trilobal polyester twisted into a smooth, round #40 thread. 

Irregular fibers  Most rayon threads are irregular. We don't use or recommend rayon threads because they are weak and usually do not hold up to common standards of colorfastness.

View Superior's Trilobal Polyester Thread Selection

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  • 1. Mason (01 August 2013 at 8:56 a.m.)

    Cool graphic!

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