Thin part with large flat surface area

[agosikwolfe]

I am trying to print something very thin, 0.8 mm tall that has a large flat surface area, about a 3 in diameter circle. What is the best way to get a good top surface? In the pictures, you can see that the top surface is not very even and the bottom has striations running across the bottom.

[JoeJ]

Your bed is going to need to be perfectly leveled to get a perfect print with something that large and so thin. Otherwise, the impact of a slightly off first layer will impact the entire part.