Five Ways to Tell if Your Fabric Is Water-Resistant

How do you tell if a fabric is waterproof or water-resistant? I bought a piece of fabric from a discount store recently, and was told it might be waterproof. It was so cheap ($4/m) that I didn’t mind if it wasn’t officially waterproof, as it would be just as cute as a windbreaker-style jacket. I took it home and did some tests to see if it was waterproof. I thought I’d share some ways to find out if your piece of fabric will repel water or not.

If you’re buying fabric for a rain jacket, or any waterproof sewing project, here are a few tips to check if it’s waterproof!

Ask! Sometimes the staff will know, especially if you have a store with helpful staff. Or if your fabric store is really small, the salesperson might also be the fabric buyer and might remember selecting the fabric for its waterproof qualities. Depending on your fabric store, this might be a good option, and then again it might not.

Look for special hangtags. Really technical fabrics will have special tags listing their technical properties. Ever been at an outdoorsy store and seen a bunch of fancy tags hanging from the jackets? Sometimes, you’ll see the same tags on the bolts of fabric too. Or look for big signs on tables, advertising this group of fabric as waterproof.

Check out the inside of the fabric. Often waterproof fabrics will have a milky coating on the inside, or a rubbery interior, or a layer that looks like shrink-wrap on the inside. If the fabric is coloured on the outside, but white and opaque on the inside, that’s a good sign it may be waterproof. If you can see a thin layer of shrink-wrap-like rubber on the inside of the fabric, it’s probably waterproof too. These rubber layers (called membranes – ew) are what makes ordinary fabrics waterproof or at least, water resistant.

I borrowed this photo from Caroline’s guest post on sewing waterproof outerwear – you can see she’s used a fabric with a coated interior.

Blow through it. This isn’t always a sign of true waterproof-ness, but it is one way to check. If you can’t blow through it, and the fabric puffs up like a parachute (reach forward and poke the fabric in front of your face to see) then it’s likely waterproof, or at least water resistant. (If air doesn’t get through, there’s a good chance that water won’t, either!) If you can feel your breath through the fabric, it may still be waterproof, just treated to be both waterproof and breathable.

Water test. Literally, drip water on the fabric and see what happens. If it soaks through and spreads (much like a paper towel) then it’s not waterproof! If the water stays on the surface of the fabric, looking like big dewdrops or bubbles, then it’s waterproof. Leave these water bubbles on the fabric for a while and see if they eventually soak into the fabric or stay on the surface.

Here’s what it looks like when water forms beads on the surface of your fabric – a good sign of what might happen when you’re out in the rain! Let’s compare that to the cotton canvas I used for my orange sample jacket:

This can be hard to do in a store. You could always bring a water bottle and give it a try – or don’t. I don’t want anyone to get kicked out of a fabric store! If your project must be waterproof, then buy the smallest amount you can (most stores will let me buy 0.1 metres) and test it at home.

Final thoughts? Even if it’s labelled as waterproof, it might not be. Especially if you shop in discount fabric stores, or the type of store where the staff don’t sew. (You know the kind I’m talking about.) The water test is the most accurate, as it’s the best way to see what will happen when water hits the surface of your fabric.

Any other tips on finding waterproof fabric, and testing it for waterproof-ness? Leave a comment below!

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27 Responses to Five Ways to Tell if Your Fabric Is Water-Resistant

  1. Marianne January 6, 2012 at 6:22 am #

    If you ask nicely, they might cut off a small piece of the fabric. A small sample. It will only be like 1×1 inch, but it might do the trick :)

    • Rachel January 7, 2012 at 4:12 am #

      What Marianne said! Most of the fabric stores around here will give you a small sample swatch. That’s what I used to check the water-proof-ness of the fabric I used for my minoru.

  2. Funnygrrl January 6, 2012 at 7:21 am #

    Great tips! Thank you.
    I think most stores will let you purchase a small amount. Especially if you tell them what it’s for. They do want you to be successful, for the most part!

  3. Alana January 6, 2012 at 7:45 am #

    Haha – I thought I was the only crazy person blowing through fabrics! Glad to see I am not alone. :)

    • Tasia January 9, 2012 at 1:27 pm #

      Haha! And I am also glad to know I’m not alone! :)

  4. Jane January 6, 2012 at 11:55 pm #

    Lol I can only imagine getting kicked out of the fabric store for spraying water on the fabrics. This post was right on time, I want to make a raincoat and not use laminated cotton.

  5. Kristen January 7, 2012 at 10:32 am #

    Thanks for this. When I picked out my fabric with my mother, we mentioned to the lady using Scotchguard to make it water repellent. The lady said Scotchguard wouldn’t work but my mom disagreed. I’m not sure who’s right but I loved the fabric so I bought it anyway and will have to live with it if it isn’t. Do you have any water-repelling spray recommendations?

    • Caroline January 8, 2012 at 9:40 am #

      Hi Kristen, I mentioned McNett‚Äôs ReviveX¬Æ, in my little Sewaholic guest post, it’s a great product that a lot of people swear by. For products that lose waterproofness over time, or even for products that never were, it works well. Just Google “McNett’s” — they have a great website.

      • Jane January 8, 2012 at 11:08 am #

        So you can use this McNett’s on basically anything and make it water repellant? That sounds like just what I need.

        • Caroline January 8, 2012 at 12:25 pm #

          There are limits to the types of fabrics you can use it on. Really, it’s geared towards technical outdoorwear fabrics that need their waterproofing restored, and nylons. And leathers. But it may work on other synthetics, it’s worth investigating.

          • Kristen January 9, 2012 at 4:35 am #

            THANKS! Sorry I missed that from your guest post. Really appreciate your sharing this – going to order now!

            • Tasia January 9, 2012 at 1:28 pm #

              Thank you Caroline for jumping in here! I’ve never used water-repellent spray before.

      • Faye June 11, 2013 at 11:22 pm #

        McNett’s is great. I was a temp worker for them a couple years back, and they’ve got some great stuff. They also treat their employees really well, and I loved working for them. :)

  6. Sue January 7, 2012 at 12:57 pm #

    I was just wondering if the Minoru pattern is really suitable for a waterproof fabric? Some of these layered fabrics may not lend themselves to gathers and elastic waist? A previous blogger mentioned using darts instead of gathers! Will this be an option on the tutorial? I am not yet ready to join the sew along but I am considering making the jacket in the near future as I need a waterproof jacket for fishing trips with my husband. Would it be better made in cotton canvas and treated with a waterproofing spray?

    • Tasia January 9, 2012 at 1:32 pm #

      Hi Sue! Lots of questions here. I think if you’re looking for a hardcore, serious waterproof jacket that you can wear fishing (I am guessing when you go fishing you get really wet? Never gone fishing before myself…) then this might not be the very best pattern. Or it might work – It all depends on how much work and extra waterproofing techniques you want to apply to the jacket. In this post, I was meaning to explain how to tell if the fabric you’ve bought might repel water, in case anyone else had bought fabric from a discount store or had fabric in their collection that they wondered might be waterproof.

      If you haven’t yet, take a look at Caroline’s guest post on how to sew waterproof outerwear for ideas on how to waterproof your jacket. In the sew-along I’ll mostly be covering how to sew the jacket according to the directions, with a few extra tips if there’s time.
      http://sewaholic.net/guest-post-caroline-on-sewing-waterproof-outerwear/

      I hope this helps!

  7. Caroline January 8, 2012 at 10:00 am #

    At two of my local fabric stores that supply technical fabrics, ladies working the cutting counter have their own spray bottles to demonstrate the repellancy or wicking properties of fabrics. I doubt you have to bring your own spray bottle — just ask!

    • Tasia January 9, 2012 at 1:33 pm #

      Awesome! Now that’s a store that knows their fabric – and how to convince you it works!

  8. Fourth Daughter January 9, 2012 at 3:10 am #

    I don’t have any tips, I just wanted to say hi after what has been a really long break! I had a busy year and didn’t keep up with most blogs last year, but looks like you’ve been going great guns. Congratulations on the patterns! And on bringing great tips to your readers too! Keep it up!

    • Tasia January 9, 2012 at 1:36 pm #

      Well hello to you too! It’s been a crazy busy year here too. Thanks for reading and for the encouraging words!

      • Aaliyah April 14, 2013 at 3:06 pm #

        Your welcome!

  9. Nethwen January 10, 2012 at 10:22 am #

    I tried the breath-through tip on my Lowe Alpine rain jacket that is waterproof and breathable. When I blew through from the wrong side of the fabric, I could barely tell on my hand placed behind the right side of the jacket. When I blew through from the right side of the fabric, I could feel moist warmth on my hand, but not air the way you would if you blew directly on your skin.

    I don’t know if this experiment helps any when buying fabric, but I thought I would share the information.

  10. saj April 5, 2013 at 6:24 am #

    On the topic of waterproof fabric and breathable fabrics, if you want some free waterproof or breathable fabric samples this is a useful link

    http://www.fabricuk.com/23-waterproof-fabrics

    Breathable fabrics and waterproof fabrics are normally measured by hydrostatic head pressure, to work out how much the fabric is waterproof and how much pressure it will withstand, if you check on the internet about Hydrostatic Head you will learn more about it.

  11. Aaliyah April 14, 2013 at 3:04 pm #

    Thanks this was really imformational.I was using this for my science fair project.”What is the best way to waterproof fabric?”I used this to see how i should test it.

  12. Joshua Kohler August 2, 2013 at 4:19 pm #

    Hello,

    Great article!

    I have some fabric that is water resistant, but I actually need it to absorb flame proofing liquid. Any suggestions on how to treat it to reverse the water resistance?

    Thank you very much!

    Josh

    • Tasia August 5, 2013 at 10:37 am #

      Hi Josh, I have no idea how to reverse water resistance. I’m not really sure if it is even possible. You might find more information from a store or supplier of technical fabrics. Sorry I couldn’t be more helpful!

  13. Roxann December 10, 2013 at 3:58 pm #

    Can you use the water resistant fabric as the backing for a quilt. I want to make a quilt to be used as a outdoor picnic blanket. I have never seen the water resistant fabric so I am not sure it can be used this way.

    • Tasia December 11, 2013 at 2:44 pm #

      I am not sure, I’m new to quilting but that seems like a reasonable idea? Sorry I couldn’t be more helpful!

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