Garment Sewing

• Nylon thread lasts longer than most other threads and is slightly stretchable, reducing the chance of breakage. This makes it desirable for garment sewing as the seams will stay together indefinitely and won't fall apart as easily due to normal wear and tear. Thread sizes 15 to 33 work well with the lighter-weight fabrics used in garments, such as cotton and polyester. Medium-weight sizes, from 46 to 92, are better for heavier fabrics like denim or thin leather.
  
  

Serging Seams

• A special type of thread called wooly nylon is typically used for serging, or encasing seams. It is a soft yarn-like thread designed for high-speed sewing that is ravel-free and extremely strong. The thread can be used in any conventional or serger sewing machines.
  
  A notable disadvantage to any nylon thread is that it can melt under the high heat of an iron. To avoid this, keep the temperature down to a lower setting and only iron on the right side of the fabric.
  
  

Top Stitching and Appliqué

• Nylon invisible or monofilament thread is often used for top stitching on quilts. Since it is colorless, the stitches take on the fabric color, rendering them nearly invisible to the eye. If a clean-edge look is desired on appliqué pieces, the monofilament thread works well to fasten down the edges without the heavy blanket stitch normally associated with appliqué. This type of thread can be difficult to work with in some sewing machines and some experimentation with the tension may be needed.
  
  

Upholstery and Home Decorating

• Because of the superior tensile strength of nylon thread, it is ideal for sewing with heavy-duty fabrics -- such as canvas, heavy leather or vinyl, and other upholstery materials used in home décor. Nylon thread is also abrasion- and rot-resistant, which makes it suitable for outdoor purposes as well. The larger thread sizes, from 138 to 277, would be appropriate for this type of sewing.
  
  

Commercial Application

• The thickest nylon thread sizes, from 346 and up, are for commercial uses such as shoe repair or auto and boat upholstery. Working with this type of thread requires an industrial grade sewing machine.