Cotona and Aerofil are both smooth, dependable Madeira threads, but their different fibers provide distinct benefits. Here is how to choose the right option for your quilting or sewing project.

Cotona vs. Aerofil at a Glance

What Is Cotona Thread?

Madeira Cotona is made from premium, extra-long-staple Egyptian cotton. The thread is double mercerized, a treatment that improves the cotton fiber’s smoothness, strength, color absorption and natural luster.

Because Cotona is made from cotton, it pairs beautifully with cotton quilting fabrics. It produces a soft, natural-looking stitch that complements the fabric without appearing overly shiny.

Cotona is available in several sizes, giving quilters and sewists control over how visible their stitches appear. Cotona No. 50 is the most commonly used size for quilt piecing. It is fine enough to help create accurate seams and reduce bulk, while still providing the strength needed for dependable piecing.

Finer options, such as Cotona No. 80, are better suited for especially delicate sewing, detailed piecing and projects where the thread should be less noticeable. Heavier Cotona threads can be used when the quilting or decorative stitches are intended to stand out.

Choose Cotona when you want:

• A 100% cotton thread for cotton fabrics

• Precise quilt piecing with Cotona No. 50

• Soft stitches with a refined, natural finish

• Minimal stretch for stable seams

• Thread for heirloom sewing or detailed quilting

• A heat-resistant thread for potholders, trivets and microwave-safe projects

• A traditional appearance that complements handmade quilts

Cotona is an especially appealing choice for quilters who prefer using cotton thread with cotton fabric. Its smooth construction and low-lint performance provide the natural character of cotton while supporting dependable machine sewing.

Cotona for Potholders, Trivets and Microwave Projects

Cotona’s 100% cotton construction also makes it the appropriate thread choice for projects that may be exposed to high temperatures.

Cotton thread will not melt like polyester can when exposed to intense heat. This makes Cotona well suited for sewing:

• Potholders

• Hot pads

• Trivets

• Bowl cozies

• Microwaveable fabric projects

• Other items intended for use around heat

For any item intended to go into a microwave, the thread should not be the only consideration. The fabric, batting and thread should all be 100% cotton and confirmed as suitable for microwave use. Metallic materials, polyester fibers and other components that could melt or create a safety hazard should not be used.

What Is Aerofil Thread?

Madeira Aerofil is a polyester sewing and quilting thread developed for strength, flexibility and consistent stitching. Its smooth surface allows it to travel easily through the sewing machine and fabric, helping create balanced, even stitches.

Aerofil No. 120 is a versatile thread that can be used for quilt piecing, machine quilting, garment construction, topstitching and many everyday sewing applications.

Because polyester fibers have some natural flexibility, Aerofil can accommodate movement and repeated stress particularly well. It is also durable, colorfast and resistant to the wear that frequently washed or heavily used projects may experience.

Choose Aerofil when you want:

• Strong, durable seams

• A dependable thread for everyday sewing

• Smooth performance at higher machine speeds

• Slight flexibility within the seam

• Low-lint polyester thread

• One versatile thread for piecing, quilting and garment construction

• Lasting color through frequent use and washing

Aerofil is a practical choice for projects that will receive regular handling, movement or washing. It can also be helpful when sewing fabrics or seams that benefit from a little more flexibility.

Because polyester can melt when exposed to high temperatures, Aerofil should not be used for potholders, trivets, microwaveable projects or other items that will come into direct contact with intense heat.

The Main Difference: Cotton vs. Polyester

The most important difference between Cotona and Aerofil is their fiber content.

Cotona is made from 100% cotton. It offers a soft feel and a traditional appearance that naturally complements cotton quilting fabrics. Cotton thread has very little stretch, which can be beneficial when accurate seams and stable construction are priorities. It is also more appropriate for projects that may be exposed to heat because cotton will not melt like polyester.

Aerofil is made from polyester. Polyester thread offers excellent strength, flexibility and resistance to repeated stress. Its smooth construction makes it a dependable option for quilt piecing, machine quilting, clothing and general sewing.

Neither fiber is automatically the better choice. The right option depends on the fabric, how the finished project will be used and the appearance you want to create.

Which Thread Is Better for Quilt Piecing?

Both Cotona and Aerofil can be used successfully for quilt piecing.

Cotona No. 50 is the most common Cotona size for piecing. It provides a balance of strength and fineness that supports accurate seams without adding unnecessary bulk. It is a natural choice when working with cotton quilting fabrics or creating a traditional all-cotton quilt.

Cotona No. 80 is finer and may be selected for miniature piecing, intricate designs or situations where an especially fine thread is preferred. However, when a general Cotona piecing thread is needed, No. 50 is the standard starting point.

Aerofil is an excellent alternative for quilters who prioritize strength, durability and smooth machine performance. Its polyester construction provides slight flexibility while remaining fine enough for accurate piecing.

For precise cotton piecing with a natural finish, choose Cotona No. 50. For versatile performance with added durability and flexibility, choose Aerofil.

Which Thread Is Better for Machine Quilting?

The answer depends largely on the desired appearance and how the finished quilt will be used.

Cotona produces soft, natural-looking quilting that coordinates beautifully with cotton fabrics. Its range of available sizes also provides more control over whether the stitches blend into the quilt or become part of the decorative design.

Aerofil creates strong, even stitches and performs smoothly during machine quilting. Its durability makes it particularly useful for quilts that will be used, handled and washed regularly.

Choose Cotona when you want the traditional appearance and texture of cotton. Choose Aerofil when you prioritize smooth stitching, flexibility and long-term durability.

Can You Use Cotona and Aerofil in the Same Quilt?

Yes. Every stage of a quilt does not have to use the same thread fiber.

You might piece with Cotona No. 50 to achieve precise, stable seams and then quilt with Aerofil for added durability. You could also piece with Aerofil and use a heavier Cotona thread when you want the quilting stitches to become a more noticeable part of the design.

The exception is a project intended for use around high heat or in a microwave. For those projects, 100% cotton thread such as Cotona should be used along with suitable 100% cotton fabric and batting.

Always test the selected thread, needle and tension settings on a fabric sample before beginning the full project. Thread size, batting, fabric density and stitch design can all affect the final result.

Cotona or Aerofil: Which Should You Choose?

Choose Cotona when you want a natural cotton thread, a soft finish, stable seams or a traditional appearance that blends beautifully with cotton fabrics. Cotona No. 50 is the most common choice for quilt piecing, while other sizes can be selected for finer or more decorative stitching.

Cotona is also the appropriate option for potholders, trivets, microwaveable projects and other items that may be exposed to high temperatures.

Choose Aerofil when you need strength, flexibility and a versatile thread that can handle quilting, garment construction and everyday sewing. Its durable polyester fibers make it especially useful for frequently used or regularly washed projects.

The decision does not have to be based on whether cotton or polyester is universally better. Consider the project’s fabric, appearance, intended use and exposure to heat.

Whether you prefer the natural refinement of Cotona or the versatile durability of Aerofil, both thread families are designed to help you sew smoothly and create with confidence.