Use Kevlar, nylon, and polyester thread to sew super strong seams and add eye-catching decorative stitching to fabric and leather
Strong, heavyweight thread lets you sew really strong seams and add eye-catching decorative stitching to fabric and leather. Kevlar thread at least twice as strong as nylon and polyester. But, it costs about five times more and only comes in yellow--in many cases nylon and polyester work just as well. Nylon and polyester threads, size 138 and higher, are our most popular decorative stitching threads. Related products include waxed thread, tennis net-like bank line, bobbins, and needles.
Thread, Bobbins, and Needles
Kevlar Thread - This thread is at least twice as strong as nylon and polyester. One pound costs at least $150 and it is only available in yellow. Nylon and polyester cost about $30 and are available in many colors. We have spools as small as 1/2-ounce so you can buy what you need.
Nylon Thread for Upholstery Nylon Thread - Nylon is the most popular thread for heavy duty sewing because it is strong, inexpensive, and easy to sew. We have all nylon thread sizes and 100's of colors. Our thread comes on 4-Oz spools for small jobs; 16-Oz spools for commercial sewers; and cases that save 10%
Polyester Thread for Upholstery Polyester Thread - Polyester looks, feels and sews like nylon and has roughly the same strength. It has better sunlight (UV) and mildew resistance and is recommended for anything that is mostly used outdoor like tents and tarps.We have polyester in all sizes and many colors. 4-Oz, 16-Oz, and cases are available.
Prewound Bobbins - If you sew a lot, prewound bobbins let you work faster by skipping the hassle of winding bobbins from your topstich thread. Commercial machines use styles "G" and "M", and heavy duty machines use styles "M" and "U". Download our free Prewound Bobbin Style Guide to identify a bobbin's style from its height and diameter.
Groz-Beckert Needles for Upholstery Groz-Beckert Needles - We sell all Groz-Beckert needles. Be sure to use cloth point needles with fabric and leather point needles with leather. Our Needle Buying Guide shows the needle points used for leather and the type of stitches they make.
Hand stitching thread for upholstery Hand Stitching Thread - Most of our nylon and polyester threads are available on 100-yard tubes for about $5. These tubes are ideal for hand sewing and speedy stitcher awls.
Waxed Thread - Waxing makes thread stronger, stiffer, thicker and more water repellant. Great for hand sewing; not so good for machine sewing because it leaves a waxy residue. We have waxed thread in about 30 colors.
Bank Line Cordage - Bank line cordage is a black polypropylene twine that is similar to tennis netting. It is exceptionally strong, sunlight (UV) resistant, and inexpensive. This makes it a favorite for: netting, knotting, outdoor survival packs, snares, whipping, bushcraft, hand sewing, lashing, and beading.
Hand sewing needles for upholstery Hand Sewing Needles - We have C. S. Osborne hand sewing needle packs.

Thread Strength (Pounds.) and Diameter (Inches)

Size Kevlar Nylon Polyester
Thin 8   3 .0064 2 .0059
46 18 .0081 8 .0094 7 .0080
69 25 .0099 11 .0015 11 .0107
92 35 .0114 15 .0133 15 .0124
138 50 .0140 22 .0163 21 .0152
207 75 .0180 32 .0200 31 .0186
277 121 .0220 45 0.231 44 .0251
346 140 .0255 52 0.258 53 .0258
410 160 .0271 73 0.283 73 0.282
554     83 0.286 90 .0330
800 225          

About Thread, Needle and Bobbin Sizes

ff you are sewing seams the thread's thickness depends on the material's thickness. An undersized thread can result in stitches breaking; an oversized thread leads to situations where the leather rips at the seams. Here is what happens as thread size increases:

  • Thread strength increases

  • Thread diameter increases

  • Sewing machine power increases. Commercial machines can handle up to size 277; heavy duty (e.g. walking foot) machines are need for heavier sizes.

  • Needle size increases.

  • Yards of thread per pound decreases.

With decorative stitching look is everything - you want the stitching to be the focal point and thread strength does not matter. As a rule, decorative stitching thread can be one size heavier than thread used to sew seams. For example, if you use size 138  for seams you can use size 207 for decorative stitching.  Here are other ways to make your stitches pop:

  • Use contrasting leather and thread colors.

  • Use large stitches.

  • Use multiple, closely spaced rows of small stitches.

Bobbins - Your bobbin thread should be one size smaller than your topstitch thread. For example, if your topstitch thread is size 207 your bobbin thread should be size 138.


Needle and Thread Size - Needle size increases as thread size increases. Our Needle and Thread Size Chart shows needle sizes for different kinds of thread and thread thicknesses.