About Thread Sizes

Today threads come in so many wonderful colors and there are many types of thread from natural fibers (such as cotton, linen, rayon, silk, wool, hemp among others) and synthetic fibers (such as polyester and nylon).  But, the #1 question we frequently receive over the years is 'What size thread is that?'

We get many 'thread size' questions.  What sized thread should I use for a table cloth? I need a thread to edge my silk blouse. What size and type do you recommend? I'm crocheting toys. What size thread should I use?  

The size or weight of thread is an important factor to consider for any fiber art project. Today, we have thread from all over the world and, because there are 5 different ways to measure thread, it can be confusing.

Fixed Weight - Fixed Weight systems use the length of the thread that makes up a given weight. Therefore, higher the number the finer the thread. So a thread ball that weighs 1 gram and is 30 meters long is classified as 30 wt thread.

An excellent example of Fixed Weight measuring system is Anchor Mercer thread:

  • Size 10 - 20 grams - Approx. 119 yards
  • Size 20 - 20 grams - Approx. 169 yards
  • Size 30 - 20 grams - Approx. 214 yards
  • Size 40 - 20 grams - Approx. 240 yards
  • Size 50 - 20 grams - Approx. 251 yards
  • Size 60 - 20 grams - Approx. 331 yards
  • Size 80 - 20 grams - Approx. 406 yards
  • Size 100 - 20 grams - Approx. 428 yards

Fixed Length - Fixed Length systems use the weight of a given length. Therefore, the higher the number, the thicker the thread. Denier count (Td) is a fixed length system that records the weight of 9000 meters of thread in grams. The Tex system (TEX) is the weight of 1000 meters of thread in grams. So regardless of the thread, if 1000 meters equals 1 gram, it is said to be equivalent to 1 Tex.

An example of Fixed Length measurement system is Finca Bobbin Lace thread. It is available in 20 & 30 weights and each spool contains 900 meters (2,952 ft) of thread.

Size - One of the original systems is called Size. It groups the threads into three sub groups consisting of Fine (approximately Size 60), Medium (approximately Size 50), and Heavy (approximately Size 20).

Our generation is so blessed with all the choices.  It wasn't that long ago when our grandmothers did tatting with size 80 cotton thread.  It was basically all they had available.

One of my  favorite thread stories involves my dad.  I mentioned to him one night over the phone that I was working on a class project for college using thread and he asked what size, to which I responded size 10. He said, "Oh, with bedspread cotton?"

To help give you a visual representation of thread sizes and their impact on your craft project, compare the tatted samples below.

You might also be interested in our discussion on choosing the right thread for your project.