I hate ironing!

There! I said it!

The only reason I’m wearing  this jacket today is because   the part of it that’s wrinkled is out of frame. Sure, ironing gets the wrinkles out, and  my clothes are nice and crisp afterwards. But it also takes forever, and I’d really   rather just throw everything in  the dryer and be done with it.

It turns out, a bunch of  scientists feel the same way. They’ve studied why your clothes  end up wrinkled in the wash,   and exactly how to get them  to come out less rumpled. So here are some science-backed ways to  help make looking sharp less of a pain. [♪ INTRO] On their long journey through the  washer and dryer, there are a lot   of factors that determine how  wrinkled your clothes will be.

And you might be tempted to start at  the very beginning with detergent. But don’t be fooled. That’s not the solution.

I mean, detergent is a liquid solution,  but it won’t make your wrinkles go away. Some scientists decided to measure  whether it has any impact on how   wrinkled your clothes are when they  come out of the washing machine. In a 2003 study, researchers threw a  bunch of fabric into a washing machine,   with and without detergent.

Then, when the cycle was done, they gave each  fabric a score based on how wrinkly it was. Technically, when they crunched the numbers,  detergent made the fabric slightly more wrinkly. But it was pretty hard to actually see  that difference in the clothes themselves.

So if you were hoping that your  detergent might help smooth things out,   that study might throw a wrinkle in your plans. Speaking of liquids you might  add to your washing machine,   fabric softener doesn’t seem to  make much of a difference either. Millennials everywhere, we can rest easy.

It might make your clothes feel softer  and smoother when you put them on. But its effect on wrinkles depends  more on how the fabric dries. In a different 2003 study, scientists  washed clothes with fabric softener and   rated each item’s wrinkliness  once it had finished drying.

Clothes that were washed with fabric  softener and then tumble dried came   out slightly less rumpled than clothes  washed and dried without fabric softener. So technically it might help, but it didn’t  turn out to be a significant difference. Now, if the clothes were washed with  fabric softener and then line dried,   they could come out more wrinkly than  clothes washed without fabric softener.

Which is the opposite of what we’re going for! Scientists aren’t sure exactly why this happens. One possibility is that fabric softener might lock   in wrinkles because it’s usually  added at the end of the wash cycle.

It comes in with the water  that rinses out the detergent. At that point, the fibers in the fabric are  swollen with water and bunched together. The fabric softener might coat  the fabric in such a way that it   locks all the bunched-up fibers in a rigid shape.

That could set some of the wrinkles in the fabric. And tumble drying might be able  to knock out those wrinkles,   but line-dried items would be stuck with them. On the whole, though, fabric softener isn’t  going to do much about wrinkles either way.

The tumble-dried clothes were less  wrinkly than line-dried clothes,   regardless of whether the wash  cycle included fabric softener. If you want neat clothes, you’re probably  better off just chucking them in the dryer,   assuming they can handle it, than worrying  about exactly how much fabric softener to use. So detergent and fabric  softener don’t really matter.

And neither does the material thickness. Some types of fabrics wrinkle  more or less than others, sure. We’ll get to that in a minute.

But a 2017 publication demonstrated that when  you’re considering two cotton fabrics, for   example, the thickness of that fabric doesn’t seem  to make a big difference in how wrinkly it gets. That’s true after both washing and drying. But different fabric types do make a difference.

In a 2020 study, researchers found that knitted   fabrics almost always wrinkle less than  woven fabrics after washing and drying. This has to do with how much space  the threads have in each material. The yarn in knitted fabrics  has more space to wiggle and   shift around than the threads  in a more tightly woven fabric.

When fabric bumps around in the dryer,  the yarn can settle back into its regular   layout and shake out some of the wrinkles  that form in the washing machine. It’s easier to knock those wrinkles out when  the fibers have more freedom to move and adjust. And that’s also going to depend on the  chemical makeup of the fibers in a fabric.

As I mentioned earlier, being soaked with   water makes a difference in how  wrinkly your clothes come out. So cloth will wrinkle differently depending  on whether its fibers attract or repel water. Cotton fibers have an affinity for water.

They’re hydrophilic. At the atomic scale, a cotton fiber has lots of   hydroxyl groups that each have  an oxygen and a hydrogen atom. This is similar enough to water,  with its two hydrogens and an oxygen,   so that the two can comfortably  mix and mingle with each other.

So, in the washing machine, when cotton  fibers absorb water and swell up,   their hydrogen atoms can form hydrogen bonds  with oxygen atoms in water or another fiber. And vice versa. Once the fabric starts drying and  all the water gets pulled out,   the fibers can only hydrogen bond with each other.

If the fabric is all bunched up,  those new bonds can lock in wrinkles. So generally, hydrophilic fabrics like cotton tend   to come out wrinklier after several washes  than they did after the very first wash. But those hydrogen bonds aren’t permanent.

Heat and the mechanical action of  flopping around in the tumble dryer can   knock some of those wrinkles back into that  original smooth surface where they belong. And some synthetic fibers, like polyester,   don’t grab onto water the same  way because they’re hydrophobic. That means they tend to wrinkle  less when you wash them.

But that doesn’t mean they don’t wrinkle at all. Once you heat up polyester fibers enough,   the individual chemical chains that make up  that polyester get a little loose and bendy. They’re too tangled up with each other  to fully melt, luckily for your shirt.

But they can bend and shift and rearrange, much  like the hydrogen bonds in your cotton clothes. For polyester, this will happen  between 67 and 81 degrees Celsius. So if your dryer gets hotter than that, the  molecules in your shirt get a little wiggly.

And once your clothes cool down, that  rearrangement might leave some wrinkles behind. But, regardless of the fabric, there are ways  to prevent wrinkles before they even form. And before I get into those  ways, it’s time for an ad break.

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Some clothes come with a wrinkle-free  treatment already applied. That way, you don’t have to think too hard  about how you’re washing and drying them. Wrinkle-free treatments have  been around since the 1950s.

Typically, a resin and a softener are applied  to your garment before it hits the shelves. That prevents the fabric from shrinking and  keeps the fibers from squishing together. As with knitted fabric, when the  fibers have room to move around and   return to their original shape in the  dryer, they’re less likely to wrinkle.

The wrinkle-free treatments  work … at least for a while. But they don’t last forever. The more clothes are washed, the  more they lose those softeners.

You can start to see these  effects in just 4 washes. One study from 2002 found that fabrics got stiffer  and less stretchy as the treatment wore off. Pretty much exactly what you’d expect  now that you know the chemistry.

Since wrinkle-free treatments aren’t a forever  solution, here’s some other things to try. One study published in 2017 suggests that doing a  bigger load of laundry can lead to more wrinkles. Which…look, I get it.

I don’t want to spend my whole  day doing laundry either. It’s super tempting to try to cram everything  into one load and then go do something else. But your clothes might come  out more rumpled for it.

As clothes bump around against the washing machine  and each other, they get more and more wrinkled. So the more stuff there is to bump into, the  more likely you’re going to end up with wrinkles. Those researchers found that  filling your washing machine   even halfway spit out some fairly wrinkled cotton.

That said, tumble drying can  knock out some of those wrinkles. So maybe you’ll be okay with  sticking a few extra shirts   in there if you’re not line drying your clothes. And there are still a few other things you can do   to minimize how much your clothes  are bumping around in the wash.

Like, a slower or gentler washing  cycle could help smooth things out. Research has shown that as a washing machine  drum rotates faster, it applies more force   to the fabrics inside, which bends them  out of shape and makes them more wrinkly. But spinning too slowly can make it hard to  get all the detergent out of your clothes.

So you might want to weigh  your options with this one. Even the amount of water in your  washing machine can make a difference. The same study found that more water in the  machine made clothes less wrinkly after a wash.

That extra water made the fabric less  likely to bend and crinkle under stress. Everyone’s washing machine is different. But a 2013 study found that using 16 liters  of water, which was on the upper end for   that machine, spit out less wrinkled linens  than a load with just 12 liters of water.

But there are two parts to every laundry cycle. The way you dry your clothes might  be more influential in the end,   as far as wrinkles are concerned. The reason tumble drying your clothes  generally leaves them smoother than line   drying has to do with the combination  of heat, steam, and mechanical action.

Together, they help relax the fibers and reset  those hydrogen bonds we talked about earlier. Based on limited data, it seems  that the longer you dry them for,   the better, at least in terms of looking crisp. The same 2003 study that looked at the  effects of fabric softener found that   tumble drying clothes for 45 minutes left  them smoother than after just 30 minutes.

Of course, even if you pay careful attention  to your washing settings, your fabrics,   the care instructions, everything, you  might still end up with a few wrinkles. And let’s be real, those  clothes are still wearable. But your final hail mary if you really need to  look crisp after forgetting a load of laundry   in the dryer are tried and true methods that  you’ve probably tested in the laboratory of life.

Like throwing the clothes back in the dryer for  a few minutes with a damp towel, steaming them,   or hanging them up in the bathroom  while you take a nice, hot shower. And if all else fails, you can  always break out the old iron. As much as I hate them, irons work. [♪ OUTRO]