Q:  How do I paint with a cross-hatched brush?

A:

var
  TheMask: TBitmap;
  TheRect: TRect;
begin
  TheMask := TBitmap.Create;
  TheRect := rect(0, 0, image1.width, image1.height);
  try
    with TheMask do begin
      Monochrome := False;
      Width := image1.width;
      Height := image1.height;
      canvas.brush.color := clBlack;
      canvas.brush.style := bsDiagCross;
      canvas.Ellipse(0, 0, image1.width, image1.height);
      canvas.CopyMode := cmSrcAnd;
      canvas.copyrect(TheRect, image1.canvas, TheRect);
   end;
   image1.canvas.CopyMode := cmSrcCopy;
   image1.Canvas.CopyRect(TheRect, TheMask.Canvas, TheRect);
  finally
    TheMask.free;
  end;
end;