The NanoDri Sweatproof Shirt uses nanotechnology to make the polyester fabric of the shirt repel water. This basically means that water repellent particles have been added during the weaving process of the yarns; hence the water repellent particles are embedded within the polyester yarn rather than externally coated with a DWR (Durable water repellent) treatment like a lot of active clothing.
The supposed benefit of having the water repellent material embedded within the fabric is a longer lasting hydrophobic (water repellency) effect. Durable water repellent (DWR) coatings are typically added to the fabric externally; hence it is a surface treatment so, it makes sense that it would wash out quicker. NanoDri does state that after 100 washes, the NanoDri Shirt still retains a significant level of water repellency. Clothing that is treated with DWR typically last about 100 washes, making NanoDri a clear winner.
The reason why the NanoDri Shirt is sweatproof and not 100% waterproof is because the NanoDri Shirt does not integrate a waterproof membrane, which is typically bonded to strong, coarse fabric. The benefit of having a waterproof membrane is that it makes any garment permanently waterproof so, the waterproofing never runs out or wear out like chemically coated fabric such as the NanoDri Shirt.
Waterproofing membrane is currently used successfully on shoes and jackets, being cleverly engineered with millions of "pores" to mimic the human skin. There is currently no waterproof membrane t-shirts or dress shirts, making nano fabric coating technology such as NanoDri an effective alternative for making wearables water repellent and breathable at the same time.
The NanoDri Shirt is internally lined with "polyester satin"; hence the lining polyester has the characteristic satin soft weave. The lining fabric is non-repellent though but, it is very absorbent so, it can catch the sweat.
This fabric layer is non-removable and needs washing just like a regular fabric shirt. There is no odor control technology integrated though, like nanosilver or silver salt chemicals, which are woven into the fabric to prevent bacteria that causes smell.
The addition of antimicrobial properties to active wear garments works really well, doing a good job of keeping garments smelling fresh for longer. The NanoDri Shirt is designed as a smart/casual button down shirt so, antimicrobial technology is probably not needed, although it would add a lot of benefit since antimicrobial clothing doesn't require washing as often. This would increase the lifespan of the NanoDri Shirt water repellency.
The NanoDri Shirt only requires a lukewarm water (40 degrees C) wash with mild detergent without the use of fabric softener because it will inhibit the ability of the under layer to absorb sweat. The shirt can handle a washing and spin dry cycle in the washing machine but it needs to dry out naturally.
It's best not putting the shirt through a dryer machine to reduce wear. There is no mention whether the NanoDri Shirt is made of recycled polyester so, it's safe to assume the shirt is made using virgin polyester. The overwhelming majority of clothing is made of polyester material, which is petroleum-based, unlike cotton or wool which are natural materials and friendlier to the environment because nature can break down natural materials.
Wool is naturally antimicrobial so, you can wear it for a long time before bad smells develop; hence the reason hikers like wearing wool (especially merino wool). For durability and quick drying though, polyester is ideal, especially with the nano coating which makes water literary bounce off. The NanoDri Shirt is available in only two sizes (Large and X Large) and you can buy it via NanoDri's website or amazon. You can also get a similar performance with the NanoDri undershirt version.