Use either the HTML control's AutoPrint method, or alternatively use the PrintPage method. Example using AutoPrint: uses Printers;

procedure TForm .Button Click(Sender: TObject);
var
  OldCur: TCursor;
begin
  OldCur := Screen.Cursor;
  with Printer do begin
    BeginDoc;
    HTML .AutoPrint(handle);
    Title := HTML .URL;
    EndDoc;
  end;
  Screen.Cursor := OldCur;
end;