Originally Posted By BZH
Silpoly is silicone impregnated polyester.


Yes, I have been researching myself a bit ... And I am happy that it is polyester based material as polyester is my favorite.
It shouldn't stretch and should be UV stable also it should not sag water comparing to nylon.

Originally Posted By BZH
Silpoly is more expensive than PU coated poly and is not quite as waterproof, though the stuff they are selling now is very good and I can't tell the difference in a tent on a rainy day. I think 190t will be quite a bit thicker than an equivalent strength silpoly.


I am planning some quite strong tarp 1.6 oz/yd2 or even 1.9 oz/yd2 silpoly ... No idea how such fabric is really strong.
There is a lot of reviews on 1.1oz/yd2 and 1.3oz/yd2 materials but not so much on heavier versions of silpoly frown