Thread is a small piece of sewing projects but its importance is undeniable. Selecting the right thread for your application ensures that you will get the best performing seams. One key factor to keep in mind is the end location of the fabric. Outdoor fabrics require threads that can stand up to the weather, while indoor fabrics have different performance needs. In this post, we’re going to look at common thread types, their uses, and the properties that make them suitable for those uses. 
Indoor vs. Outdoor Applications
Outdoor applications require specific traits such as UV resistance, high strength, and resistance to abrasion, mildew and often saltwater to last in all weather conditions. For indoor applications, the UV resistance becomes less important and abrasion resistance and stretch becomes more important. Upholstery applications, for example, require a thread that has a good elasticity so it will give and recover when you sit on it.
4 Common Types of Thread
Polytetrafluoroethylene (PTFE)
These threads will outlast your fabric! PTFE threads like Tenara or Helios carry a lifetime guarantee. These threads are unaffected by exposure to UV rays, harsh cleaning agents, pollution, saltwater, rain, snow, cold, and rot. PTFE threads carry a lot of performance benefits, but they are a little pricey. They are much more expensive upfront, but will require less re-stitching over the lifetime of your project. These threads come in only a few colors, but of those, translucent is the most popular as it will blend in with any color fabric. PTFE threads are used for outdoor, marine, and awning applications. PTFE thread is very slippery and can be tricky to sew. It doesn’t require as much upper tension as polyester thread, so you’ll need to adjust your sewing machine accordingly. It also helps to use a smaller than normal needle, to ensure the thread creates the proper loop for the hook to catch. We recommend using Serv7 needles with PTFE thread.
Polyester
Polyester is known for its strength, durability, and low shrinkage and stretch and is the most common thread for outdoor applications. Over nylon threads, polyester thread has superior resistance to UV rays and moisture but much of its strength is lost after prolonged exposure to sunlight. Polyester thread comes in a variety of colors to match your fabric, but the colors will fade to white over time in the sun. We recommend using polyester thread for outdoor cushions and upholstery, sails, outdoor canvas covers, boat covers, awnings, tents, and tarps.
Nylon
Nylon is one of the strongest synthetic threads in use today. It has a high strength-to-size ratio in comparison to polyester thread and is also known for its flexibility and stretch. The high tensile strength of nylon makes it ideal for heavy fabrics used in home décor. The added elasticity is also ideal for upholstery applications. While nylon is a great general-purpose thread, we do not recommend it for outdoor applications. Nylon does not have the UV resistance of polyester thread and will not last as long outside.
Monofilament
A strong, clear thread, monofilament resembles fishing line and comes in different weights suitable for various applications. Monofilaments can be made from polyester or nylon. Made from a single continuous fiber with a specified thickness, monofilament is strong and uniform with a high resistance to abrasion. However, it lacks flexibility and can feel stiff or scratchy. Lighter monofilaments can be used for quilting or tacking, and heavier versions can be used in upholstery or canvas projects. Monofilament is considered an indoor use thread. As you can see, choosing the right thread can make a big difference over the lifetime of your projects.
For more thread guidance, check out our Thread & Needle Recommendation Chart. This quick reference chart pairs up needle types and thread sizes for most all of our fabrics. Get the perfect thread for your next sewing project at www.sailrite.com.
Have you ever had a mishap with using the wrong thread? Share your stories in the comments.
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