How does on bring imposter to front (rendered last)?

[Jacobus]

I rendered a chessboard where all of the chess pieces are imposters. How can I bring a certain chess piece to the front (rendered last)? I tried the following code:

GLDirectOpenGL.MoveLast;
 GLDirectOpenGL.Visible := False;
 GLDirectOpenGL.Visible := True;

AND

GLDirectOpenGL.MoveFirst;
 GLDirectOpenGL.Visible := False;
 GLDirectOpenGL.Visible := True;

Can someone maybe hint me in the right direction?