Originally Posted by Achilles_
Would the polyester make the shirt hot? (Nike dry-fit seems to all be poly)
Nope. I know conventional wisdom says polyester doesn't breathe, but that simply isn't the case with the modern performance blends. Many of the serious guys I play with wouldn't even consider cotton on a hot day. Here is a good explanation:
The positives about polyester: 1) As most have noted, the moisture wicking properties of polyester are far superior to cotton. Why? Think of it this way...cotton is a cellulosic or protein based fiber. When it gets wet, it wants to "absorb" moisture, which gives you those big sweat ponds under your arm pits and down your back. It also makes the shirt heavier and sticks to your body more. polyester is an oil based product and as we all know, oil and water don't mix. So, polyester "repels" moisture. There are 3 types of moisture wicking technologies on the planet right now: 1a) Channeled polyester (most popular brand would be Coolmax): If you looked at the end of this fiber, it would look like a "C". It has a channel that runs through the middle of it so that moisture can spread and evaporate more quickly. 2a) Topical moisture wicking applications: These are the most common. These are put on once the fabric is knitted, they simply run it through a bath of moisture wicking chemicals and let it dry. This is the least expensive technology, but will also wash out anywhere from 2-15 launderings. 3a) Spun in technology (most popular brand would be Sorbtek): This technology is actually spun into the yarn when it is in the melted spinning point to make the yarn. This technology is typically considered the best technology on the planet and will outperform most anything on the market. Plus, it will not wash out. Things to remember when brands are making their decisions of what technology to pick: Who has ever returned a shirt because they said it didn't wick moisture enough? Most brands (Nike, Under Armour, etc.) will use the topical technology simply for that point. As someone noted before, if you use fabric softner or a dryer sheet, you will bind up that moisture wicking technology and that shirt will lose all of it's properties. 2) For those that say that cotton "feels" better: Typically, that is because you have found a shirt that has a bad "denier to filament ratio"....what that means is this....denier pertains to the size of that yarn and the filaments are the "hairs" or "strands" that make up that yarn. If the denier number, let's say 70 since that is the most popular size on the market, is much more than the filament count, let's say 34 as that is the most popular (cheapest) filament count on the market, then the shirt will have "scratchy" feel to it. Now, if the brand uses a filament count that is higher than the denier count, then we have what is called "microfiber"....this means that the shirt may be 70 denier/200 filament, which gives it that "silky" feeling. You may be asking yourself, why wouldn't everyone do microfiber then? Well, first, it's more expensive. Second, it is much easier to "pick" or "grab" onto something and pull the yarn out giving it a snagged look. It also abrades more easy, letting those filaments break and show looking a little worn. 3) What technologies are great with polyester?: There are plenty of technologies on the market that offer some of the following attributes that are much better than cotton: a) UV Protection: You can achieve a 50+ UPF protection in some technologies. b) Comfort performance: Some technologies can cool the surface of the skin by up to 3 degrees and warm up to 3 degrees. c) Summer black protection: Some technologies can reflect sunlight on darker colors so that it doesn't heat up in the summer time similar to white fabrics. d) Anti-microbial protection: Inhibits the growth of bacteria caused by sweat so your shirts don't stink over time. e) Anti-fading: Won't fade similar to cotton. f) Cotton-like feel: Example would be Reebok's Speedwick technology that has the performance of polyester, but the feel of cotton. Always iron polyester on your irons polyester setting (getting too hot will melt the polyester) and you can use fabric starch (it will just tend to get white flakes in some cases).