Just finished making two customized coffee mugs and I was nervous and excited. They came out amazing and it was so easy. How long should I leave them in the oven and what set temperature should I use? Update: (Just watched from another video: Let mugs set for three hours. To seal or set the water decal designs, place in oven at 230 degrees Fahrenheit, bake for 15 minutes.) Note to those trying this technique for the first time: Read instructions on the water decal paper to find out how long to leave designs in water because they might differ. Also, I sprayed my designs three times because they did bleed after first try (which was two times). I don't think I sprayed enough of the acrylic spray on them. Again, thanks for such a great video.