Why A Cotton Undershirt May Not Absorb Sweat

If you’ve ever noticed that your cotton t-shirt or undershirt does not seem to be absorbing sweat, you may find this interesting.

Dear Mr. Undershirt Guy,

I have worn black hanes tagless tees for years (under shirts and buy themselves too).

The recent ones I purchased feel sort of plasticky and don’t seem to absorb sweat.

Any idea what is happening?

Any recommendations for a different brand?


Rules to wearing undershirts

Thank you!

Best wishes, Andrew

Non-Absorbent Cotton (Water Repelling)

heya andrew,

good to hear from you buddy and thanks for your question!

if the hanes tagless t-shirt you got are still 100% cotton, then my guess is that they have treated the fabric with some form of coating to perform some function (either moisture repelling, softening, etc.).

the most common treatment apparel manufacturers use to soften fabric after it has been knitted is silicone.

tip: you can search google for “silicone softeners for textiles” to learn more.

i wrote about this earlier this year, where a good friend from china in the knitting business provided some great insights.

there are other softeners as well, but the one i hear about most often is silicone.

knit dyeing machines processing fabric
knit dyeing machines processing fabric

from what i understand, there are two fundamental ways in which softeners like silicone get applied in the clothing manufacturing process:

  1. after the fabric is made, before it is made into clothing
  2. after the fabric has been made into a garment, the garments are sent in big batches to “dye” (or laundry) houses, where they are post-treated with different processes to achieve the desired result

for example, with #2, t-shirts, undershirts, underwear, or any other garment can be sent to a dye-house and be “garment dyed” and softened at the same time.

in other words, an uncolored fully assembled garment can be sent to be dyed, softened (aka adding silicone to the wash), distressed, etc.

the best way to tell if your garment has had a silicone or softener applied to it is to dribble water on it.

if the water beads, something has been added to the fabric at some point in the manufacturing process to make it softer.

mind you, the silicone or softener will wash out over time, so it’s not a permanent issue.

Cheap Black T-Shirts

if you’re in search of a cheap black t-shirt, then you probably should look at uniqlo, costco, sams, kmart or other value brands like old navy.

you could also checkout mark-down stores like ross, tjmaxx, or marshalls.

if you’re in search of something better, you should checkout this article:

(many of the brands that offer v-neck will also offer crew neck, if that’s the style you want)

hope that helps!

Fabric Softeners Kill Absorption

Got this info from my pals over at Staples Promotional Products (link):

Greetings Tug,

I just saw your piece on the t-shirts that no longer absorb sweat.

There is one other self-induced reason why a shirt may not absorb sweat.

If a person uses laundry softeners or fabric conditioners, this can, over time, have the same effect as commercial softeners used at the time of fabric production.

The same problem is an issue with towels that no longer absorb moisture as they once did.

Dryer sheets are a culprit in this problem.

– JB


Sweat Proof Undershirts

3 thoughts on “Why A Cotton Undershirt May Not Absorb Sweat”

  1. Thanks for the tip about Not using fabric softeners or dryer sheets. I switched to wearing all cotton shirts(from another article about fabric absorption), but didn’t know why I still felt so sweaty/wet. Hopefully I’ll notice a difference when i stop using softener/dryer-sheets.

    Btw, is there anything I can do about my excessive sweating?, it’s very annoying and embarrassing. I walk to the end of the block and I’m already soaked in sweat, i have to keep folded up paper-towels in my pocket to wipe it off.

    • heya jarret,

      good to hear from you buddy, and glad to know this article has been helpful.

      as far as i know, there is nothing specific you can do about your excessive sweating, other than try to manage it using known methods such as sweat-mark or sweat-through resistant clothing, clinical/stronger antiperspirant, changing often, etc.

      i have read some articles related to the topic, where people have been trying and/or prescribed different oral medications that help subside some of the sweating symptoms, but they usually always result in some other side effect.

      one of the more common side-effects i’ve read about is very very dry mouth, to a somewhat uncomfortable level.

      i don’t recall the names of the medications off the top of my head, but i may have saved it somewhere — maybe even in an article or comments.

      if i can find the info again, i’ll post it here.

      • Okay,thank’s for the advice Tug, I’ll have a talk with my doctor about my excessive sweating and see if there’s anything I can do.

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