The HSI 1st Gen Professional Ceramic Flat Iron is designed with tourmaline-infused ceramic plates, generating negative ions and allowing smaller water molecules to penetrate into the hair shaft to reduce frizz and static. Built for durability and lasting results, the floating plates give the flexibility to flip, curl or straighten your hair – all with a single iron.
Size matters. With plates too big or too small, you’ll have to make multiple passes. This exposes your hair to high heat longer and increases the risk that you’ll do damage. According to Janine Jarman, owner and operator of acclaimed Hollywood salon Hairroin, a 1-inch-wide plate will do for most people, and if you want to use your iron for anything other than straightening, like creating curls or waves, you’ll need a 1-inch plate; anything larger won’t make the waves or curls tight enough. She also pointed out length is important too. “You need plates to be at least 3 inches long, or close to it, so you’re not spending a ton of time with small sections.”
The curling iron can also have either a spring-loaded, Marcel, or clipless handle. Spring-loaded handles are the most popular and use a spring to work the barrel's clamp. When using a Marcel handle, one applies his or her own pressure to the clamp. Clipless wands have no clamp, and the user simply wraps hair around a rod. Most clipless curling irons come with a Kevlar glove to avoid burns.
This feature is particularly beneficial for users with naturally wavy or curly hair, which can have a tendency to easily snag in hair styling tools. This floating design, combined with the heat sensor, also ensures that your gorgeous curls won’t become permanently damaged just because you decide to straighten things out a bit for an evening or two. After all, those curls are coveted by beauty pros the world over, and you never want to damage them just because of a styling trend!

Dylan also loves this Karmin iron. "The plates are coated in tourmaline which helps for an easy glide," he says. Fighting frizz with infrared ions, Dylan suggests that it "makes this iron better for super coarse hair." Bonus points: it also has different voltage settings for international use. The jetsetter in you will be thankful as you globetrot glamorously.


“The temperature of the iron can determine the curl pattern on hair that tends to fall easily, as you might need a higher heat to lock in the pattern closer to the root,” she added. “The internal components of the irons also can determine the curl pattern, and that is why it is important to invest in custom, high-end tools that contain internal heaters that go the entire length of the barrel. The higher the heat, the stronger the curl will essentially be. Low heat will produce a softer finish.”

The Bio Ionic worked well on all of our testers’ hair, but it’s best on drier hair with a medium thickness. We spritzed testers’ hair with some keratin smoothing treatment, but the Bio Ionic did a lot of the heavy lifting to make our hair feel softer. The tool gets hot, but not too hot to grip, and it excels at creating the silky volume you want without making your hair pin-straight and flat. One tester put it perfectly: “[The Bio Ionic] is the Rumplestiltskin of hair straighteners. It’s turning straw into gold.”
If you have trouble remembering to unplug your flat iron before heading out, you’ll appreciate the Chi Air’s one-hour automatic shutoff. Since people have preferences regarding auto shutoff this wasn’t a criteria for us, but our testers thought it was helpful. One tester said she often leaves her flat iron on in the morning and invested in a timed switch to make sure it’s off. So if you’re forgetful when it comes to turning off your tools, then auto shutoff might be an important feature for you.
If you are unsure what exactly your hair type is (or if it has changed over the years, which happens more often than you’d think!), check out this incredible overview by the hair professionals at Redken! Don’t stress if you have combination hair (i.e., fine and curly or thin and straight) either; we recommend choosing a hair straightener based on your biggest hair complaint and focusing on that problem first. So, if your curls are driving your nuts, you will want to select a hair straightener with higher temperatures, thin hair needs moisture, etc. You’ll find that your entire hair type can usually benefit from the extra TLC!
When shopping for the best hair straightener for your unique hair type, it can be difficult to decipher all of the different styles and specs. That’s why we’ve done the hard work for you and created this all-inclusive guide to finding the best hair straightener for your unique head o’ hair, so you can spend less time scrolling through pages of products and more time rocking your new dream do’!
Automatic shutoff isn’t a feature we included in our criteria since people have varying opinions about it, but we liked that the Chi Elite has this. Especially for new users who might forget to turn off their flat irons. Like the Chi Air, the Chi Elite will shut off after one hour. However, if you’re working with kinky hair, auto shutoff may be a problem. Traditionally this hair type will take longer to straighten due to detangling and the fragility of the hair.
Unlike the plain Jane ceramic plates of most hair straighteners, the tourmaline-infused ceramic plates in the CHI Air Expert Classic Tourmaline Ceramic Flat Iron are designed to keep your hair healthy during styling. Specifically, the tourmaline helps to more evenly distribute the heat during use which, in turn, creates a higher number of negative ions for shinier and healthier looking hair with each use. This reduces the static electricity created, meaning you get a sleeker, smoother style.
There is a slide at the base which holds the device from opening all the way (easier for storing) but if you slide the piece it allows the flat iron to open all the way. The instructions inside the box don't explain this part, so at first I thought it didn't open very far, but once I figured this out, it became a breeze to use. Speaking of the instructions, they are listed in English, Spanish, French, and German. (I think... I don't speak/read all of those languages, but I believe that's correct.)
EDITOR’S CHOICE: As the only hair straightener we reviewed featuring Keratin-infused ceramic plates, the LumaBella Keratin Duel Touch Hair Straightener is our top choice for the healthy, shiny hair you’ve always dreamed wanted! With a unique, floating plate design and smart heat sensor, this hair straightener is ideal for a variety of hair types and reduces breakage and splitting by up to 50%.
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