Having some trouble making strawberry fruit leather for the first time. I'm pureeing frozen strawberries in orange juice then spreading the puree on parchment paper that I put on a pan. I then put it in the oven at 175 degrees. I've tried leaving it for 1 hour, 2 hours, or 3 hours. But it always ends up being really thin and sticking to the parchment paper to the point that it's impossible to separate from the paper. What should I change in my steps above? 
Try a little cooking spray (pan release) on the pan, or, another option would be to use a silicone mat.  