Just in case anyone here is interested, here's the results: In the first photo, I splattered some water on the bottom of the bag. You can see the water forming into droplets on it, but doesn't get absorbed by the bag. Sorry, I wasn't brave enough to do this test before waterproofing it. so I have no idea how the water would behave on a non-waterproofed lambskin bag. In the second photo, I had tilted the bag and let the water droplets roll off the bag. I wanted to see the "behavior" of the water. After that I simply wiped the leftover water droplets with a cloth. And the bag looks the same as before. No water damage. Oh yes, I used the Collonil Waterstop spray initially. And since I also have the Cadillac Water Seal, I also used it to double waterproof it. It's probably redundant, but I just wanted to try the product. The results I got from just using the Collonil Waterstop spray are the same as using both the Collonil waterstop spray and the Cadillac Water Seal. I didn't see much of a change in texture or color of the bag with the waterproofing I did. Of course my human eye may not be good enough to detect slight changes, if there's any. I took these two photos in the bathroom under the white Flourescent lighting, and very close-up - that's why there's quite a fair bit of light reflection. The bag looks essentially the same before and after the waterproofing to my human eye. I do not know if the results I got would hold for bags of other colors. I also did the same to my GST Caviar Black. I'm not sure if it's necessary to waterproof caviar but I did it anyway.