Title: Draw transparent text on canvas
Use Brush.Style for the Form.Canvas, if you want to set background color of text like a color of form. And use TextOut, if you want to draw text on the canvas.
procedure TForm1.Button1Click(Sender: TObject);
begin
with Canvas do
begin
Brush.Style:=bsClear;
TextOut(10, 10, 'Hello');
end;
end;