Lowest setting, wave it back and forth over the area, apply some pressure from behind the canvas to smooth out the wrinkles. As it cools, the wrinkles will definitely be less noticeable. I find the light/white canvas is much thinner so it doesn't take much. For thicker canvas, just more time and go slow.When you use the blow dryer do you see the canvas smooth out as you dry it? Or you have to let it cool down after drying it to see the change?