Cloth Diaper Mysteries Solved! Wicking, Stripping and PUL

I cloth diapered for more than a year before I had a decent comprehension of certain cloth diaper terms.  The most mysterious ones for me were wicking, PUL and stripping.

Is wicking good or bad?

Do I say P-U-L or pull?

Stripping?  What the heck?


Wicking is so simple you’ll kick yourself.

Is it good or bad?  Both.

Wicking is the transfer of moisture from one place to another.  It is good when moisture is wicked away from baby’s skin through a stay-dry fabric like microfleece, suede cloth, microchamois (pronounced micro-SHAMY) or athletic wicking material.

Wicking is a bad thing when moisture finds a weak spot or exposed area to leak out of.  For example, if your pocket insert isn’t full tucked in the diaper the wet insert will wick (transfer) to clothing or the outer fabric of the diaper.  Or if the inner fabric around baby’s legs isn’t rolled in moisture will wick to clothing, sheets, furniture…

Another very common instance of wicking occurs during oversaturation of the soaker material. This crosses over into more of a leaking issue but the same concept occurs.

At this point the moisture can transfer freely to the stitching and then outer fabric.  All of this is easily visualized when considering how the capillaries in our body work or if you have ever performed carnation and dye experiment.

How do you prevent wicking?  Make sure everything is tucked in nice and neat to the waterproof cover and change baby often.

I say potAYto, you say potAHto

Personally, I call polyurethane laminate P-U-L.  But, many a diaper-making friend call it pull.

Polyurethane sounds bad, right?  Let’s look at what it actually is and then you can call it whatever you want.

Polyurethane laminate is 100% waterproof, flexible and durable.  A great combination for diapering products.

To make PUL it is laminated by the use of heat onto a (most commonly) cotton, polyester or polyblend fabric.

I’m no chemist but I know polyurethane is not natural.

Polyurethane is a polymer — a class of chemicals derived from petroleum. Polymers are created when small chemicals called monomers chemically react to other monomers and form a long chain of compounds. This chain is known as a polymer. The precursor monomer for polyurethane laminate is toluene 2, 4-diisocyanate, known as TDI. According to the National Institute for Occupational Safety and Health’sInternational Chemical Safety Charts, this substance is possibly carcinogenic to humans. Prolonged inhalation exposure of the substance may cause asthma or skin sensitization. Polymers are generally stable, but some people worry that the toxic monomers can break down and become reactive. Other people see no hazards in using PUL, even on a baby.

This all sounds very discouraging.  But, according to Shirley of Bummis Diapers (via New and Green Baby, Co.)

Firstly, all of the fabrics used in these diaper covers meets or exceeds US Government CPSIA standards indicating that there are no diisocyanates present in the polyurethane lamination.  Diisocyanates are a respiratory hazard for which inhalation and dermal contact should be avoided.  Other potential toxins that are standard for CPSIA testing include hydrogen cyanide, pthalates, formaldehyde or lead.  While these are not expected to be present at any level in PUL testing confirmed that the levels of these potential toxins were zero.

On the making of PUL – PUL is formed by reacting polyol with diisocyanates in the presence of suitable catalysts and additives.  This makes the thermoplastic polyurethane (TPU) from initial stages of the polymerization.  This process is completed in a factory within a controlled environment.  Once the polymer is made, these initial substances cease to exist as they were and have formed another compound known as TPU.

The newly created TPU is an inert material.

The Material Saftey Data Sheet for TPU states that it only releases harmful chemicals above 428F degrees.  This is true for all plastics.  If any TPU was heated to such a high melting point, they could release toxic fumes but this is not the case in a stable product with regular use.

Now I’m feeling a bit better about my cloth diapers with PUL/TPU.

When shopping for PUL use these tips from Jaime of Celtic Cloths:

The solid color PUL fabric I sell is a thin 100% polyester knit fabric laminated with 2 mil of the polyurethane film.  The prints vary and may be 100% polyester knits, a cotton/polyester blend, or 100% cotton wovens.  All are laminated with 1 mil of polyurethane and are coated with a durable water resistant coating.  The reason for the difference is that the woven cottons result in a less pliable fabric once they are laminated.  Using a thinner laminate helps keep the fabric as stretchy and soft as possible.  Whenever you have a cotton fabric outer, you have a greater opportunity for leaks, the water resistant spray gives extra waterproofing properties to compensate for the cotton content.  If your child is a heavy wetter, or you want the stretch and reliablility of the solid color PULs, choose a print that is a 100% polyester knit.

The breathability is still lacking in either of these compounds which can cause problems for long periods of time like overnight.  Alternatives to PUL and TPU are wool and fleece.

Why do cloth diaper moms always talk about stripping??

Before you get your panties in a wad, stripping cloth diapers is completely G-rated.

Stripping simply means removing the detergent, rash cream, ammonia crystals, minerals or other yuckies that have built up over months of using and washing your cloth diapers.

I say “simply” but there are times when this process is anything but simple.

How do you know if your cloth diapers need to be stripped?  If they smell like an animal died, ammonia that burns your nose hairs, leak suddenly and furiously or don’t appear clean through other signs then you should consider stripping.

Always strip cloth diapers that are cleaned.  Then run a hot wash with no detergent.

The method you use for stripping your diapers can vary depending on whether you have hard or soft water.

For soft water, vinegar is a great stripper.  The acid in vinegar neutralizes pH, breaks down the urea and alkaline detergent buildup in your cloth diapers.

When I lived in far north Dallas I would do a vinegar soak about once a quarter.  I had a top loader at the time and soft water.  By adding 3 cups of vinegar to a full basin and soaking the cloth diapers for a few hours I would eliminate the severe ammonia buildup.

A 1/2 to 1 cup of vinegar can also be added to the final rinse of the stripping process to ensure all the soap is released.

However, vinegar can react with the minerals in hard water and cause yellowing and stink issues.  If you have been using vinegar and have hard water, stop using it, strip and see if that helps your problems.

Other popular methods for stripping cloth diapers are the use of RLR, Funk Rock or Calgon.

Calgon is a water softener and helps to break the “seal” on the diapers from hard water minerals therefore, allowing the fibers to be cleaned.  RLR and Hard Rock are used by soaking diapers and causing buildup to be released from the fabric.

RLR can be purchased from many cloth diaper stores or Amazon.  Simply follow the directions on the package for use.

According to the Rockin Green website you should not soak items with PUL/TPU longer than 1 hour.  Microfiber, bamboo and hemp can be soaked for longer periods safely.

Soaking in an HE machine isn’t impossible.  When the water pours in press pause and add 3TB Funk Rock for a soak.  If you have a top loader simply fill the basin and stop machine.

After doing all these things it is important that you take steps to prevent buildup.  Are you using a cloth diaper safe detergent, cloth diaper safe rash cream and rinsing THOROUGHLY?

These 3 steps will eliminate many hours of problem solving!

*affiliate links are included in this post. Thank you for all your support!

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About Autumn Beck

Autumn is a wife, mother, homeschool teacher, friend and most important a follower of Christ. She began cloth diapering in 2005 and has experienced many joys and trials throughout the years. You can read more from Autumn over at

View all posts by Autumn Beck

34 Responses to “Cloth Diaper Mysteries Solved! Wicking, Stripping and PUL”

  1. Heather Johnson Says:

    I pronounce PUL as “pool.”


    • Kristine Says:

      Me too. Never really got why some people call it ‘pull’… P.U.L. If you say the letters past enough it sounds like ‘pool’. It just makes more sense to me. :P


  2. Jesseca Says:

    These are great tips for a new to cloth momma! Thanks for sharing your knowledge!!


  3. Amanda Says:

    stupid question: how do you know if you have hard or soft water? i live in columbus, ohio and have city water. We have been dealing with stink right out of the dryer. I stripped them by using 1/3 cup bleach in a hot wash which was recommended by another site. this happened a few weeks ago and it came back quickly so i had to do it again. She also had a rash and i was using Aquafore and CJ’s butter and im not sure if that is cloth friendly or not. There are no stains on my diapers or anything, they just smell like urine even after washing.


    • Laura Says:

      Hey Columbus! Me too. You most likely have hard water. I’m guessing you have figured that out by now. Had the same problem w/ our cloth. Used Rockin Green’s Ammonia Buster. Problem solved.


    • Kristine Says:

      Ha! Another fellow cbus resident here! Most of the local city water is at least moderately hard throughout central Ohio. If you’re on fb, we have a great local group that rocks at troubleshooting issues, especially dealing with the hard water. ;)


  4. Faith Says:

    I forgot to click the button to get the answer. :) See….need. really. small. words. now..


  5. Faith Says:

    Hi Autumn!

    This post is old now, but since I’m ‘new’ to the cloth diapering world – I’m hunting up all your great articles. (friends sent me to you…Grateful for Grace and another mom from the middle east :))

    Stripping is on the agenda for today. Ugh. We’re having major pee out every possible place on EVERY. SINGLE. DIAPER. going on here. Plus, yes, blow your face off smell.

    When you say the dipes need to be clean first – does that mean I need to do the regular washing of them THEN start all over with the cold cycle and the strip cycle??? Or can I just use the strip cycle to be the clean ’em up cycle?

    I’m needing really small words and maybe even pictures these days. I blame the hormones. :)


  6. Barbara Says:

    Hi Autumn! I love your site! I really love all the information you provide! I am still fairly new to cloth diapering so I am always coming here for tips. I know this article is a couple weeks old but I was wondering what EUC means? I’m sure its probably simple and i’m just slow picking up all the terms! Thanks again for your site!


  7. Amanda Bridgewater Says:

    I am in the habit of soakung my Flip stay dry inserts and cotton prefolds in a full washer of water with 3 tablespoons of Rockin Green Classic or hard rock over night. It seems to get the smell out of them better for me. Is this setting me up to ruin my dipes?? Help!


  8. Erin Says:

    I have the burn your eyes ammonia smell in my diaper pail…I have been adding Calgon to my wash because I have hard water and I also did the Hard Rock and Funk Rock treatment. However I still have the killer ammonia smell…ugh! I am not however, having any issues with absorbancy however I can see where I have used diaper cream (cloth safe)which i thought wasn’t going to stain the diapers. I think my diapers are clean but I really hate the ammonia smell because my daughter is a curious little girl and she has opened her pail a time or two. Good thing she doesn’t stand high enough to get a smell of the ammonia.


    • Kristi Potts Says:

      Is it just your pail that has the smell issue, and NOT the diapers? Have you tried cleaning out your diaper pail? The stink tends to “set-in” to the plastic over time making the ammonia smell get worse as time goes on. Next time you pull the diapers out to wash, wash your diaper pail as well. Then pour straight vinegar on a rag and wipe down the entire inside of your pail (everywhere you can reach!)
      Also, have you tried an “open pail”? Which just means to leave the lid off of your diaper pail. It sounds crazy, but I know a lot of mama’s who swear that it has stopped their stinky-pail issues!


    • erin Says:

      We use the arm and hammer fridge deodorizer. hubby just attached it to the metal rail that is part of the lid with a plastic wire tie/ tie wrap. seems to work great for about a month and then we have to change it.


  9. Lauran Says:

    Thanks for the article! Very helpful.


  10. christine Says:

    I had the stink of death issue after using the diaper twice. I figured it was my own ineptitude lol. But I wanted to wash in hot. The instructions say cold though. Will the PUL seriously melt off if I do stripping every month or two in hot water?


    • Autumn Beck Says:

      I haven’t experienced this but it is always a possibility.


    • Kristi Potts Says:

      It really depends on how the PUL was made (there are two different processes – chemical bonding, and heat bonding) and where it came from (whether from a trusted supplier that makes PUL for diapers, or if they are making it for other uses.) For example: most of the PUL (aside from the Babyville brand) that JoAnn Fabrics sells has a care label of “wash cold only” and even “handwash only”!! They have a horrible reputation for bad PUL since their supplier was not making it for the intended use of diapers. It has been known to delaminate after just a few washes (or even just ONE wash) using hot water. That company makes heat bonded PUL and the adhesive they used obviously had a really low melting point. Most heat bonded PUL uses an adhesive that has a much higher melting point (higher than your washing machine could go unless you have a sanitary cycle.)
      I would trust the directions that the manufacturer has given you, since they know the source of their PUL best.
      I would, however, write them an email to let them know that they shouldn’t be expecting their customers to wash diapers in ONLY cold water since that doesn’t do a very good job at removing all of the urine/waste. If it’s anything other than just a diaper cover it really should be washed on at least warm to thoroughly clean it.

      PS In case you haven’t figured it out I make diapers, too. And I pronounce it “PULL” ;)


  11. Amanda Says:

    You read my mind! I was just yesterday thinking if it was pronounced pull or P-U-L. I was just at a fabric store and noticed they had a whole baby section with it for sale there and i almost had a heart attack thinking of all the diapers i could make but figured i should probably learn how to pronounce it first! haha thanks!


  12. Angie Luby Says:

    My son is 6 months and I am now using the same diapers I did with my daughter- I started cloth later with her. He keeps getting a red rash on the skin above his penis. It lasts a long time even with diaper friendly cream so i would put him in a g disposable to clear it up and then it comes back. Could he be getting an ammonia rash, have heard of this but not sure exactly what that is. Or could he have very sensitive skin that doesn’t do well with the bamboo tri fold insert directly on his skin?? My daughter never had this problem….


    • Autumn Beck Says:

      I would first cut a strip of microfleece and lay it on top of the diaper and see if that helps. He may need a stay dry barrier. You can purchase stay dry liners or make several yourself.


    • Kristi Potts Says:

      If it’s not that he needs a stay-dry layer then I would be thinking it’s a yeast rash. And unfortunately yeast can’t be cured with regular diaper rash creams (in fact a lot of them will actually FEED the yeast!) And you can’t just treat your son for the yeast like you would with disposable diapers, you have to treat your diapers as well. It doesn’t take long for yeast to multiply and grow, so you have to make sure that you treat ALL of the diapers and that you continue to treat them for at least several days after the infection is gone. Otherwise it could just pop right back up again.
      I would pick up some Lotrimin AF or Monistat (yes, THAT monistat) to replace your rash cream for a couple of days to see if that helps.


  13. melissa Says:

    I was curious about stripping-thank you! My daughter just turned 5 months today, her diapers have been in use about 4.5 months, and I just noticed that some of them aren’t as absorbent as they were before. LOVE your page <3


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