WPRichText transparent?

procedure TTransparentForm.chTransparentClick(Sender: TObject);
begin
  WPRichText1.Transparent := chTransparent.Checked;
end;

procedure TTransparentForm.FormCreate(Sender: TObject);
begin
   WPRichTextLabel1.Transparent := true;
   WPRichTextLabel1.ViewOptionsEx := [wpDontClearPageBackground];
   WPRichText1.Transparent := chTransparent.Checked;
   WPRichText1.ViewOptionsEx := [wpDontClearPageBackground];
   WPRichText1.BorderStyle := bsNone;
end;

procedure TTransparentForm.PaintOnControl( ctrl : TControl; Canvas : TCanvas; offx, offy : Integer );
var x, y : Integer;
    p : TPoint;
begin
    p := ctrl.ClientOrigin;
    Dec(p.X, ClientOrigin.X);
    Dec(p.Y, ClientOrigin.Y);
    Canvas.Pen.Color := clBlack;
    Canvas.Pen.Width := 0;
    y := p.x mod 10+offy;
    while y<ctrl.Height do
    begin
       Canvas.MoveTo(0,y);
       Canvas.LineTo(ctrl.Width,y);
       inc(y,10);
    end;
    x := p.y mod 10+offx;
    while x<ctrl.Width do
    begin
       Canvas.MoveTo(x,0);
       Canvas.LineTo(x,ctrl.Height);
       inc(x,10);
    end;
end;
procedure TTransparentForm.PaintBox1Paint(Sender: TObject);
begin
    PaintOnControl( PaintBox1, PaintBox1.Canvas,0,0 );
end;
procedure TTransparentForm.WPRichText1Change(Sender: TObject);
begin
  WPRichTextLabel1.Assign(WPRichText1);
end;
procedure TTransparentForm.WPRichText1PaintDesktopBackground(Sender: TObject;
  Canvas: TCanvas; R: TRect);
begin
    Canvas.Brush.Color := Color;
    Canvas.FillRect(R);
    PaintOnControl( WPRichText1, Canvas, 0, -1 );
end;