How To Choose A Thread

By Monica Lam

Today, we will go over Thread and everything you need to know about choosing thread for your project! It may sound a little silly that we need to have an entire post about this, but you’ll be surprised how something seemingly minute like thread and affect your project dramatically!

Consider all of the following:

  • Type of Thread
  • Content / Fiber of Thread
  • Weight of Thread
  • Color of Thread

Type of Thread

You may be thinking… “What do you mean, “type”? Aren’t they just those small spools of thread offered in many colors at the craft store that fit into my Home Sewing Machine?”

True, most people can get away with randomly choosing a small spool of thread at your local craft store. Growing up, my mom’s sewing box was filled with all kinds of colors in those small spools. But, truth-be-told, there are many types of thread available if you’re truly looking for it. From Metallic Threads to Elastic Threads, know of what you are in need.

As a beginner, you’ll likely do fine with a #50 or 50 wt. General Purpose thread. You’ll sometimes see this listed as 50/3 on the thread spools.

Content / Fiber of Thread

Most thread manufactured these days are 100% Spun Polyester. This is the most common fiber you’ll find anywhere you go. Especially the ones that come in a wide array of colors. They are durable and strong for sewing.

Next, if you are in search of a natural fiber, you’ll likely be able to find 100% Cotton Thread in limited colors. By limited, I mean white and black. Really, it’s uncommon to see Cotton Thread in a huge variety of colors as Cotton Thread is typically used when coupled with other natural fiber fabrics like Cotton and Linen for garment dye purposes. We won’t talk too much about garment dye formulations, but essentially, Natural Fibers react to certain dyes differently than something synthetic like Polyester. If you use white Polyester Thread on a white Cotton Jersey t-shirt and send it to a factory to dye, you will likely get a dyed garment where your thread stays white.

If this is intentional, then congrats, you’ve just made a garment with contrast stitching. However, most basic t-shirts you see for sale come with matching thread colors. It’s impractical for garment companies to buy many color fabrics and many color matching threads, so most manufacturers buy white cotton fabric and white cotton thread. Sew thousands of t-shirts, then separate quantities to dye into colors.

If you get more advanced in sewing or do any specialty projects like Leather, you may need Nylon Thread in heavier weights. For stretchy projects like Swimwear and Activewear, you may need Wooly Nylon.

Weight of Thread

This part is a bit tricky, as the standard for thread weight hasn’t really been consistently used throughout the industry. In most Hobby or Craft stores, you’ll see measurements by weights or numbers: 50 wt or #50. According to this method of measurement, the bigger the number, the finer the thread. If you see 50/3 that means 50 weight thread in 3 plies. Plies means how many individual strands of 50 weight threads that are twisted together. The more plies, the more durable and strong the thread is.

Another measurement you’ll sometimes see is Tex 50 or T-50 . This method of measurement is a more scientific and has been adopted by the International Organization for Standardization. Tex uses 1,000 meters of thread per gram as a point of measurement. So, Tex 1 refers to 1000 meters of thread weighing 1 gram. Tex 50 means 1000 meters of thread weighing 50 grams.

That’s probably more specific than you need on a practical level, but essentially… the bigger the Tex number, the heavier and thicker the thread. Medium weight Tex threads run a range from Tex 21 to Tex 70, but keep in mind that natural fibers and synthetic fibers vary in weight, so compare with like-fibers when judging which thread weights you need for your projects.

The Tex measurement is more often seen when buying thread from thread manufacturers who supply on an industrial level such as Garment Factories and Design Houses. Threads for industrial manufacturers come in tall spools with more yardage per spool (5000 yds per spool generally). This will last a lot longer than the palm-sized spools from the Craft store, so I strongly encourage everyone to get used to purchasing larger spools in the Tex measurement if you are working on a larger project.

Color of Thread

This is a no-brainer, but it’s worth mentioning. As I said earlier, determine if you are working with fabric that has already been dyed, or if you intend on dying your fabric. If you are dying white cotton fabric, I would suggest using white cotton thread if you want it to all match. If you have colored fabric, you may want to color match it the best you can with color thread that blends in. This is great if you’re concerned sloppiness or mistakes may show on your work. If you’re ready to brave the world of contrast topstitching, then go crazy, grab yourself a different color thread than your base fabric, say--neon stitching? Then just have fun!