STL Question

[LTH]

I have an STL file I want to print but I want to have the background to be solid white. At the present time it has no background color. I've attached a pic of the file to see what I'm talking about. Any help with this would be appreciated. Thx

[BallBearing]

A little bit late answer and I'm not sure if I understood the question correctly. But make a square and lay the wings over it. Intersect & clean. A lot of work perhaps. Works if the bottom of the wings is flat enough.