I've never had this happen Gene, I use Mig washes and these are enamel based, don't know if a water based one would wash off but I still don't think so. I've had a few people tell me that they've used water based colors when trying this system and I am still to hear that it has been washed out. If you scribe those lines nice and deep, I just can't see that happening. You do have to remember that you can always add a bit more wash even after painting, that's the beauty of scribing the lines deep. Just make sure that there is no sanding debris when doing so.