NikwaxNikwax Cotton Proof, 1000ml, Waterproofing for Cotton, Polycotton, and Canvas, Adds Water Repellency

I was a little nervous given the variability on some of the reviews but I washed my M65 field jacket with tech wash and then cotton proof in my washing machine and I have to say that I'm pretty impressed, water beads up on rolls off similar to what the other field jacket user reported. Short of waxing, cotton will never be truly waterproof but I would say that if there were light rain or showers in the forecast I wouldn't be concerned.In the bottle the proofer smells a little like Elmer's glue with a trace of vinegar but I can't detect it at all on the dried garment.

This product works well for light sprinkles of water. I used this for my motorcycle jeans as its original water proofing has worn away. Right after washing I noticed the cloth felt quite different. I tested it with some water spray and it did a good job. However, if it was patted with water or a wet towel the water will soak into the jeans. This will work for puddles and splashes. However, when I get on my bike and there is some water dew on the seat, the water still soaks into the pants... eventually.

This is a great product. My husband is a surveyor and he was in the rain and tall wet grass all day and stayed dry. He also said it cut the wind really well and it was 30 adn 40 MPH wind that day. If you do not do these extra steps the product won't work well. If you do these extra steps it works great!First we ran our washer with vinegar ( put 2 to 3 cups of vinegar in where liquid detergent goes and hot water to remove detergent and fabric softener build up through out my machine. It is in your machine even when you cannot see it. I hadn't used vinegar in awhile so we done this procedure twice. We washed my husbands clean pants from the closet with vinegar only (2 cups) on a long wash and no fabric softener. Actually we ran them a second time on a short wash with vinegar and then a rinse/spin only. Then we soaked his pants in a 5 gallon bucket of water with the product for a several hours. We dripped them out well and put them on a mini short rinse and spin. We dried them with HOT HEAT.It works!

As others have noted in reviews, it looks and smells like diluted Elmer's white glue. Make sure you shake well and make sure to follow instructions.My deviations from instructions:After cleaning clothes (jackets and pants) with regular detergent, I ran them full cycle with a cup of vinegar. Then removed them and ran a full cycle of just water and vinegar (no clothes) to clean out any soap.Put clothes back in, filled the machine with water (all items needed cold), added half the bottle, let agitation cycle run, then stopped machine and let everything sit for at least an hour.Re-Started machine at beginning, let it run through all cycles uninterrupted. Put clothes in dryer without a static/softener cloth on lowest heat.Did this with Wrangler cotton blend cargo work pants, a no-name poly cotton jacket, knit poly winter hat, an LL Bean barn jacket (Teflon treated from manufacturer), and a Carhartt heavy cotton duck jacket (no factory waterproofing).The LL Bean, and Carhartt jackets got a spray down of silicone after. Both bead water well, the LL Bean jacket not as well as the Carhartt.The pants bead water a bit, they do not soak up water like a towel anymore, but they are not impervious to water (impervious should not be expected anyway).I do plan on using this stuff annually on all of my usual work outerwear.

It works wonders with cotton/ cotton blend clothes alreadytreated with DWR from THE START from the factories.This product is for reapplying already DWR-ed clothes/ gearsDo not expect this cotton proof to make regular heavy cotton things into mil-spec'd rain gears.It kinda worked on my Pendelton canvas jacket.Just like me, experiment this product on your old cotton/ cotton-blend clothes.

The pants in the pictures are 100% cotton and were cleaned as per the directions from Nikwax prior to applying the product. I ran this pair through with one additional pair of pants using the recommended amount of solution and at the recommended washer setting and temp. This was the result - it was poring outside when I took these pictures, so I figured it would be a good test. Water hit the pants and soaked right in, no resistance whatsoever. You can see one bead sort of rolling off in one of the pictures, but that was only because I had the pants at an angle when I took the picture. I figured I would go do a short three mile hike to see if it made any difference as you can see, the parts of the pants exposed below my poncho are completely soaked through (the pic of my feet). This stuff didn't even provide any level of repellency, let alone "proofness". I've used Nikwax products in the past and they generally do what they are supposed to, so I was disappointed with this one. One star, but would be zero if I could give it a zero. It's not worth sending back, so I may do another wash cycle using more product to see if makes any difference.