I have a bunch of fabric from wal-mart- I told everyone I know that if they saw sil-nyl there to pick it up for me- now I have at least three or four different types of nylon- how can I be sure what is what- Some of it seems very heavy and coated on one side-I was told that it is probably DWR-How can I be sure??? I did test it by cutting a swatch off and securing it over a large glass of water-then turning the glass up-side-down for 24hrs- there was no leak-thru - would DWR leak or not? and if it is DWR- does anyone have any suggestions on projects for it?? as for the other fabrics- I'll have to work on identifying them as well so that I cam make all kinds of things this winter!!!!