I have been trying a few things to go on the Terra Rosa Gear quilt and bag cover but also on a few of the tarps and have found that Tyvek (1443r at very least) takes very well to the DWR treatments you buy in the outdoor shops. I found that the spray treatment was a little easier and a little quicker then the wash in formula. Both have worked very well and Im pleased with the end result.

Here is a picture of some treated Tyvek