I have had the same issue. I ended up getting the eco-flo dyes. They have worked well for me. It takes a bit of practice to avoid streaks. I gave up the fieblings because it totally ruined two pieces that had taken a lot of time to do. Basically I wiped it on and off, came back a half hour later and the pieces looked like bad Cuir Boille. Hard, cracked and not a bit of flexibility. Used oils on the pieces and the are still hard, cracked and not a bit of flexibility. That was fieblings brown. I had bought a bottle of black at the same time, tried it on a test piece and got the same bad results. (I am just wiping dye on with wool dauber, then wiping off excess with cotton and buffing slightly. Then I let the piece dry.) tossed the bottles and bought the eco-flo water based dyes. No such problem since.