A discussion about water-tightness (Gore-Tex etc)

By which meathod some clothes are made waterproof?

There are only two available methods to achieve absolute water-tightness:

1. Whole construction (or a single external layer only) from a completely waterproof material like PVC or (non woven) nylon. Its main drawback is that it doesn't permit skin perspiration, making it non suitable for prolonged use. Additionally it is always thin (in order to be light and flexible), thus it's easy to tear it (so water can enter). Therefore, this solution is limited to add-on raincoats temporarily used when it rains. They are cheap and suitable for daily use.

2. A very thin "breathable" foil internal layer. It also acts as a wind barrier. However, it is very sensitive to tear-off, creasing, chemicals, machine washing, sweat etc. So the duration of such a foil is not greater than a few years, depending on the treatment. After that point, it will be not waterproof! I 've heard that they also do not perform well at high ambient temperatures (a discussion about this at  Deti's Transalp page, currently in German only). Such a foil is the Gore-Tex. Manufactured by the US company Gore, (probably) the inventor of this technology. It is already used from (probably) all the mountain equipment manufacturers. It is used in the most expensive motorcycle garments (provided by DAINESE, BMW, FRANK THOMAS, IXS et al.). Maybe it provides the largest amount of pores per area unit, that's why it's the most expensive foil, so many clothing manufacturers use alternative foils like:
Sympatex (in boots from SIDI and UVEX).
Miporex (in pants and jackets from CLOVER).
Breatex (in gloves from UVEX).
Hipora (in gloves from COLORI.and PHEDRA).
Reissa. (in jackets from RICHA).
Aerotex (in jackets from MOTOLINE).
Vapas (in pants & jackets from SHOEI).
Nibo (used by ORINA)
Sheltex.
Porotess etc.

Any other solution (including Teflon coating and "oiled" leather) could never be 100% water-proof. The more sensitive to water intrusion areas are the sewings and the non thermally welded joints. Consequences will be clearly noticeable after 10-20 min. of rain or after a violent splash from a car passing by...
If you really insist on partially waterproof synthetic clothes, you may use a Teflon spray like Scotch-Gard or (preferably) some special waterproofing treatment (liquid) like those used on mountaineering garment.