What Are Sailboat Sails Made Of | Fabrics & Inspection Tips


When I was recently looking for new sails, I wondered what Fabric Are Sailboat Sails Made Of? So, I did some research and testing to find it out.

So, What Fabric Are Sailboat Sails Made Of? Sails are made from a wide variety of fabrics, from natural fibers, such as flax, hemp, and cotton in various forms of sails canvas to synthetic fibers such as polyester, nylon, aramids, laminate and carbon fibers.

Modern sails are crafted from innovative materials to withstand the adverse weather conditions they face on the water and to last much longer compared to the sails in older boats. Let’s discuss this topic in more details.

What Fabric Are Sails Made of?

Modern sails are mainly made of the following materials:

KevlarCarbon Fiber
SpectraLaminate Sails


Polyester fiber is the most common sailcloth used around the world, it is often known by its trade name Dacron. Dacron’s properties include great resiliency, high UV, fatigue, and abrasion resistance.

With excellent flex strength Dacron is one of the most affordable sailcloth in the market. Polyester fibers are more waterproof than traditional choices because it has four layers of protection.

Flex strength is the ability of a cloth to regain its strength after being folded back and forth.


Widely used for spinnakers, it is lightweight material, with high strength, excellent abrasion resistance, and flexibility, it also shows good UV resistance.

However, it has a low modulus, allowing too much stretch for upwind sails.

Nylon is a rugged material, however, it is very susceptible to damage when exposed to chlorine and other chemicals. So, bear in mind, if you have nylon sails, never use chlorine-based bleaches when washing and cleaning.


This type of fiber is predominantly used for racing sails and can also be used in laminated cruising sails.

Its properties include high strength, higher strength-to-weight ratio than steel, and a greater modulus than Mylar and Dacron.

It loses its strength with flexing, folding, and flogging, and does not resist UV light well.


Spectra sails are usually used on spinnakers and on high-performance sailboats where the sails are replaced frequently.

Spectra’s properties include excellent UV resistance, superior breaking strength, excellent low stretch, and high flex strength.

However, over time Spectra is very much prone to permanent elongation under a sustained load which causes its shape to change.

This is also the main reason why Spectra is usually used for spinnakers on high-performance sailboats.


On par with to Spectra, Dyneema is exceptionally strong fiber produced by Dutch firm DSM.

Dyneema is more widely available in a variety of sizes and is growing rapidly in popularity.

Dyneema’s properties include a high strength-to-weight ratio with outstanding low stretch and abrasion and excellent UV resistance qualities.


This is a polyester film which is at the center of laminate sails. The film acts as a base to which everything else is glued to.

Its properties include excellent tensile strength, great dimensional stability, and transparency. Mylar is used extensively in racing sails.

Carbon Fiber

Carbon fiber is the best performing fiber used by the sailmaking industry today. It is a high modulus fiber made from carbon, it is virtually unaffected by UV exposure with exceptional low stretch.

Carbon fiber sails are extremely durable and flexible, however, the only disadvantage to carbon fiber is degradation from flexing. I have seen fiber comparison charts rating carbon and kevlar virtually the same score for flex. So, it is not that bad after all. They are much costlier.

Laminate Sails

These fabrics are made of layers of film, taffeta and scrim glued and laminated together under extremely high temperatures, as a result, a light, strong membrane sail fabric is created.

Laminate fabric combines technical efficiency, durability and easy handling.

Its properties include excellent tear strength and excellent wrap stretch performance. Laminate fabric is high in UV ray resistance.

The main attribute of laminate cloth is its ability to retain their shape which makes the sailboats fast. Laminates are generally lighter than woven sails and have a higher modulus.

Laminate sails are significantly more expensive than other type sails. But they last for a very long time.

How Long Does A New Sail Last?

Majority of the wear happens at the start of the journey when the sails are unfolded and pull up and likewise at the end of the journey rather than in open water where your boat may sail for hundreds of miles.

This process is so personalized and different from one sailor to another and even from one journey to another that it makes is very hard to give a lifespan in terms of the number of years or sailed miles.

One thing is certain though, the wellbeing of your sail is not affected much by mileage directly, the two most essential factors in aging of the sails are flogging/flapping and UV exposure.

Besides, flogging/flapping can quickly break down all types of sailcloth. UV light deteriorates the stitching and the sailcloth itself so, it is very crucial to cover your sail if it is not being used.

Additionally, the well being of your sails are depending on some more factors that are listed below:

  • What type of fiber/cloth is the sail made of
  • How the sails are used and
  • In what weather conditions have the sails been used
  • Amount of care it has received, etc.

As your sails age over time, they stretch in high load sections and obviously, it causes the shape to change.

With that steering will become hard and even it will affect your speed.

Before the sails are stretched out of the shape, it is a good to idea to replace them, as this will make a significant difference to the way your vessel sails.

How To Inspect Your Existing Sails

In this section, I will discuss my general guidelines on how to inspect the sails’ structural strength and overall well-being.

To start out, the sails need to be spread in a wide area to make inspecting effective for you.

At least you should be able to work from edge to edge to edge cause a lot of time the damage is to be found in the leech, inboard batten pocket ends and spreader patches.

So, once the sail is spread properly go over all the seams and the edges. And you will be looking for rips in the stitches, making sure all edges are in good shape.

Make sure you have colored masking tape or just blue house tape to mark along when you spot any issue during the inspection.

Here are some areas that you might want to look closely when inspecting your sails:

  • Check all the seams all around: Polyester treats are weakened over time so, be sure to check the seam of the sail carefully.
  • Inspect all the edges (support tape)
  • Inspect luffs edges thoroughly
  • Inspect sail window: Polish and clean them but if they are in bad shape replacing them will be a good idea.
  • Look out for Holes and Rips: Holes and rips are not uncommon even for new sails. Holes and rips could be fixed by stitching patches on the damaged area.
  • Check Sails slides, Grommets and Shackles: They may be broken and may need to be replaced
  • Inspecting batten pockets and tell tails: batten pockets are known for being problem areas from abrasion, old elastic, or even mission or broken battens.
  • Inspect the Spreader Patch: especially on a Genoa, a spreader can do a significant amount of damage to the sail so, make sure you check it properly and the spreader is in a good shape.
  • Inspecting Leechline Cleats and Velcro: Leechline is tensioned and fastened down with velcro sometimes, or cleats. So, run through and be sure they are in good shape.
  • Assess the Corner Rings: Rings that are secured with webbing at the corners of the sails should be inspected thoroughly. Look for frays in the webbing and the stitching on the webbing.
  • Check the sail numbers and logo if you have one.
  • Inspect the headboard: They are seldom a problem, but still, we want to inspect them completely to make sure they are in good shape.

A great tool that I like a lot is the speedy stitcher, it is a super handy tool. It can stitch the seams or webbing without you have to bring down the sail. You can do it on the spot.

Click here to check Speedy Stitcher on Amazon.

Best Practices For Buying A New Sail

Good sails ensure speed, sailing efficiency and safety on your vessel. When your sails are in great shape, your boat heels less, reduces the tendency to round up into the wind in storms and making steering and controlling the boat more pleasurable.

Please consider the following tips before buying a new sail:

  • Before you look for a sailmaker you need to inspect your sails completely and find out if your sail is repairable. Follow the steps here above for a full inspection.
  • If your sails are beyond the repair and you choose to go with new sails then first you need to decide what type of fabric, and fabric thread count you want your sails to be made of.
  • Once you made your choice, it is advisable to find local sailmaker. Choosing local sailmakers will save you loads of time and money. As many sailmakers want to take their own measurement.
  • One additional benefit of choosing a local sailmaker is that you can expect the sailmaker to do a “test drive” under sail, in different conditions. However, be ready to pay for sailmaker’s time.
  • Once you have the contact details of the sailmaker(s) in your area you approach them and ask them for quotes. Choose the best sailmaker possible, please note that the cheapest quote may not always be the best choice.
  • Also, this is the time that you want to let them know what type of boat is the sail for and the type of sail you wish for, the measurement, etc.
  • Communicate how many mainsail reefs you need, as this affects the cost, versatility and also safety. If you are day sailing, one reef is sufficient, for coastal and offshore sailing two are needed, etc.
  • It is recommended to consider battens: communicate with sailmaker the quantity, type and location of battens on the sail.
  • Finally, ask your sailmaker to include all hardware and labor charges in the quote.

Related Questions:

Are Sailboat Sails Waterproof And Mold Proof?

So, Are Sailboat Sails Waterproof and mold proof? Depending on the material the sails have been made with, almost all of the modern sailboat sails are resistant to water, and mold to a certain extent.

Modern sails are designed to withstand the adverse sea conditions they face and last much longer compared to the cotton sails on the older boats.


I am the owner of sailoradvice. I live in Birmingham, UK and love to sail with my wife and three boys throughout the year.

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