Ties That Bind: Choosing the Right Thread

by Cathy Ellsaesser, posted on

The right thread choice is so important to the quality and enjoyment of your sewing, quilting, and embroidery! Yet, with so many types out there, which one is best for your current project? I have used 40wt thread, usually polyester for much of my sewing needs. However, with my latest project, a quilt with lots (and lots) of piecing and overlapping seams, I am pretty disappointed in how some of my piecing seams look using that weight. So I started searching on the web for others’ opinions about the right thread for different applications. I have so much to learn!

Choosing the right thread has to take into consideration the composition of the thread, the weight of the thread and the number of plies in the thread. Choices of compostion include cotton, polyester, nylor, silk, or metallic.  Choices of weight vary from 12wt to 70. How many strands are there —  2 ply or 3 ply? And what is long stapled thread? So in this blog, I’ll try to cover most of these, and, hopefully, help our readers understand thread a little better, too, and determine the right thread for their projects.

Please note, this blog is only about thread used for home machine sewing, embroidery and quilting, not any type of hand sewing.

What Is the Right Thread Compostion for your Project?

Bubba Gump goes on and on about shrimp. Just imagine what he’d say if he was talking about thread! You’ve got your….


cotton thread placed in picture of cotton bolls

Twist together some fine staples (fibers) from a cotton bole and you’ve got cotton thread.  This thread is strong with a medium sheen. The natural fibers of cotton help grab the fabric and create a tight seam. Beware, though. It is difficult to tell low-quality from high-quality cotton thread. The fiber length (the staple) of the cotton and the method of processing determines how much lint the thread leaves behind as you sew.

Grades of Cotton Thread

Graphic illustrating short, long and extralong cotton staple

Lowest grade = Regular staple (or short staple) cotton. Thread made from this grade is never marked as regular or short staple. It is labeled only as 100% cotton or mercerized cotton, because having a short stapled cotton thread is nothing to brag about. Short staple cotton threads has a lot of lint. They are weaker than regular and extra-long staple cotton threads.

Medium grade = Long staple cotton. Thread made from this grade of cotton is labeled as long staple. Long staple cotton threads have less lint than short staple cotton threads.

High grade = Extra-long staple cotton. Thread made from this grade of cotton will be labeled as extra-long staple cotton. This is currently the highest quality cotton fiber available.


Good old polyester!  For unmatched versatility, get polyester. It is truly multi-purpose. It can be made to look and feel like different fiber types, such as cotton and silk.

I use polyester thread for my embroidery. I also love monopoly thread (a fine monofilament thread)  for invisible stitching on a quilt top. (One trick I learned in using monopoly thread is to take a marker and color the end of the thread if you need to manually thread the needle. It makes the end of the thread so much easier to see.)

Floriani Polyester Embroidery


Rayon has a very high sheen and a soft touch. It is created by pressing cellulose acetate (usually made from wood pulp) through small holes and solidifying it in the form of filaments. Warning, though about rayon, it is often not colorfast. Also, it is not as strong as polyester. It is, however, a great embroidery thread and makers such as Madeira have a wide variety of rayon thread that produces beautiful embroidery.

5 spools of Madeira Rayon Embroidery


Nylon threads are synthetic just like polyester.  You might find nylon monofilament thread or fuzzy textered thread like “wooly nylon”.  I love wooly nylon when I’m serging a rolled hem, but other than that, I wouldn’t sew or quilt with nylon. It can melt under an iron, it sometimes discolors, and often becomes brittle with age. The polyester monofilament (monopoly) is far superior for quilting.


Silk threads are fine and make stitches that seem to disappear. These threads are also a good choice for appliqué and when beads are added to the fabric.


Want to embellish a Folk Art quilt or project with a homespun look? Then wool thread might be just what you are looking for. Wool threads are typically thicker than other threads.


Multiple layers of materials wrapped and twisted together create metallic threads. They are typically made from a core of nylon or polyester covered with a decorative product. Quality metallic threads also have an outer coating that protects the delicate metallic layer.

I love metallic thread, but it can be a frustrating thread to use. There is a wide range of quality among the different manufacturers of metallic thread. Check out one of my very earliest blogs, Don’t Get Your Tinsel in a Tangle: Embroidering With Metallic Thread  for some hints on using metallic thread for embroidery. Get a good metallic thread, and enjoy the beautiful sheen and excellent stitch quality that it gives you.

Floriani Metallic Embroidery 4 spools of Madeira Metallic Embroidery

Additional Guidance on Using Metallic Thread

  • Use a Topstitch or Metallic needle sized #90/14
  • Loosen top tension
  • Position a stacked spool (see below) so that the thread unwinds directly from the side of the spool as the spool rotates. Don’t unwind a stacked spool of metallic thread over the end of the spool. This results in added twist and increases the tension on the thread as it passes through your machine.
  • If using a cone of metallic thread, the thread must unwind straight up over the top of the cone, not from off the side.
  • Use a smooth polyester thread in the bobbin.


A friend of mine uses water-soluble threads for many of her basting needs. Wash your project when done and these threads dissolve. It’s just the right thread  for any task where temporary stitches are needed.

Package of Wash-a-way basting thread

Fusible threads are used to sew a typical seam, but when pressed they stick the sewn fabrics together. Binding and appliqué are two possible uses for fusible threads.

Fusible Thread

Solar-active thread changes color when activated by sunlight.

There’s also glow-in-the-dark thread, perfect for that Halloween quilt or a grandchild’s t-shirt.


Relax and Unwind

Most spools of thread are wound one of two ways, cross-wound or stacked. The thread comes off of each type of spool differently. Rule of thumb is to have the spool oriented to that the thread comes off the way it was wound.

stacked and cross wound spools

The thread on the right in the picture above is cross-wound. The thread is wound on the spool in a criss-cross way, resulting in a pattern of “X’s” on the spool. The varigated purple thread on the left in the picture above is stacked. In contrast, the thread is wound on the spool so that it stacks one row above the other, resulting in a pattern of straight lines on the spool.

Use a horizontal spool pin for cross-wound spools. This allows the thread to feed evenly off of the top of the spool.  Use the spool along with a foam pad and spool cap to help keep the thread from wrapping around the pin. However, set the spool vertically if you are are using a thread stand that loops the thread up above the machine.

Stacked spools work best on a vertical spool pin. This allows the thread to feed evenly off of the spool. Use the spool along with a foam pad to help keep the thread from wrapping around the pin.

What is the Right Thread Weight (Size)

The weight or size of thread is an important consideration for any sewing project.

Ever wonder why the smaller the number the thicker the thread? Well, it relates to the length of the thread in kilometers required to weigh 1 kilogram – the longer the length of thread needed to reach that weight, the finer the thread. So the higher the number, the thinner the thread. So, if a thread is 40wt, then 40 km of that thread weigh 1 kg. Likewise, for 30 wt thread, 30 km of thread weighs one kg, because the thread is thicker and weighs more per km than a thinner thread. So, the bigger the number the more thread it takes to weigh 1 kg.

Thread sizes from 12wt to 60wt

You might see the size designation depicted as a fraction, such as 50/3. The first number reveals the thread’s weight, and the second tells us the number of plies.  Thus, a 50/3 thread has a weight of 50 and is made with 3 plies of fiber.

IMPORTANT NOTE: Thread labels vary. No. 50, #50, 50 wt, and 50/3 are not necessarily the same. They are different measurement standards. Make sure when comparing weights that you use the same system.

5 Quick Tips About Thread Size

Making proper adjustments relative to different thread weights makes sewing, quilting, or embroidery projects more enjoyable.

  • Heavier threads make your stitching more visible.
  • The thread size measures the thread’s thickness.
  • Thread tends to get stronger as it gets heavier.
  • The tension on your sewing machine will need adjusting when you switch thread weights.
  • Try to use a needle where the eye is 40% larger than the thickness of the thread.

The Right Thread for Embroidery

Most polyester and nylon thread made for embroidery is 40 wt.

Floriani Polyester Embroidery thread

Need a thicker thread? Then try 30 wt or even 12 wt. I love the way 12wt thread gives a hand-embroidered look to some projects.

3 spools of Floriani 12wt thread

If using heavier thread, then be sure to use an appropriate sized needle (I like a top stitch size 14) and adjust tension as needed. Again, a 60wt bobbin thread will reduce bulk, and yet, not detract from the heavier thread look.

Need a thinner thread? Both Floriani and Embellish have a 60wt polyester embroidery thread that is perfect for delicate embroidery and lettering.

5 spools Embellish 60wt thread the right thread for lettering

Also, Embellish has a line of 40wt matte thread. In the past, embroidery thread all had a sheen to it to give the embroidery a special look. But you know, matte thread also gives embroidery a special look. Many embroiderers use a combination of traditional “shiny” embroidery thread and matte thread in one design. This gives the design an added dimension. Int the picture below, Lynn used matte thread for the background shading and rocks, and then embroidered the puffins with the “shiny” Floriani polyester.

Using the right thread for this puffin design includes Floriani polyester and Embellish matte thread

Unfortuneately, it’s hard to see the difference in a photo, but stop in any of our locations to see the effect that matte thread has on embroidery designs.

The Right Thread for Piecing

All-cotton threads are the best choice for piecing quilting fabrics. Help avoid future wear at the seams by choosing the right thread that’s no stronger than the fabric. That means it’s best to avoid polyester threads and overly strong cotton threads. A hefty thread can also affect seam allowances and accuracy because it takes up too much space in the seam and causes excess bunching. So in my research, I realized I need to use 50wt thread to do my pieceing, so that the seam doesn’t take on additional bulk.

The Right Thread for Quilting

Many quilters  only use 100% cotton thread in every part of the quilting process. Thicker thread weights, like 30/40, make the quilting stitches stand out more. If you do use a thicker, “fancy” thread on top consider using a 50/60 basic thread in the bobbin. Not only does this save money, I find that the quilting stitches look better when quilting on a home sewing machine. However, I like to use the same weight top and bottom when quilting on my longarm.

4 spools of Signature quilting thread

The Right Thread for Sergers

Choosing the right serger thread for a project is as important as choosing the right serger for yourself. The serger has to  construct a seam while finishing the raw edge of the fabric. Serger thread is finer than standard sewing machine thread to avoid the bunching and pulling that cause bulky seams. Buy the best quality thread you can afford. Cheaper threads allows lint and fuzz to build up faster.

I have a PFAFF Admire Air 5000  and it will not autothread cheaper serger thread like Maxilock. It does love the Aerolock from Madeira, though!

Madeira Aerolock the right thread for sergers

Oh, and there’s some really cool varigated and decorative threads available for sergers from Madeira.

Package of varigated Madeira Aerolock Serger Thread     

The Right Thread for General Sewing

Obviously, the project your working on will dictate what type of thread to use. You might need a delicate thread for sewing sheer fabrics or a heavy thread for top stitching on denim. Regardless of what your project is, however, it is important to get the right thread that is high quality.

The many thread guides, pretension and tension disks help maintain the sewing machine’s tension. In most of the newer machines, the tension disks are hidden inside a plastic cover. This protects the disks from dust and damage, but, on the other hand you can’t always see whether fibers are accumulating in the tension disks. You’ll realize it when your stitches don’t look like they should due to poor tension, or you get thread breaks.

Get Your Right Thread Right Here!

At Rocky Mountain Sewing and Vacuum, we only sell high quality thread.

For everyday sewing, we have Metrosene Polyester from Mettler. If you prefer cotton, there’s Mettler’s Silk Finish Cotton.

Mettler Metrosene Polyester thread Mettler Silk Finish Cotton The right thread for general sewing and machine quilting

Beautiful embroidery is yours with  Floriani, Embellish and Maidera threads.

Wall of Floriani Thread  

Madeira Rayon embroidery thread  Madeira Metallic Thread

For Sergers, Maidera thread and for quilting we have 30 wt Sulky Blendables, 40 wt Signature and 50wt. Finesse.

Sulky Blendables quilting thread 4 spools of Signature quilting thread Finesse 50 wt quilting thread

Need to know more? Check out the videos availble at Thread Therapy for much more information how to pick the right thread for your project.

As a special thank you for being our customers and reading our blog, here’s a coupon to buy one get one free embroidery thread. Just click on it and print it. Enjoy and happy sewing!

coupon for embroidery thread