function GetHPPrinterIndex: Integer;
var
  i: Integer;
begin
  for i := 0 to Printer.Printers.Count - 1 do
    if AnsiContainsText(Printer.Printers[i], 'HP') then
    begin
      exit(i);
    end;
  Result := -1;
end;

procedure TForm1.Print1Click(Sender: TObject);
var
  iPrinterIndex: Integer;
  iPrinterName: string;
begin
  iPrinterIndex := GetHPPrinterIndex;
  Printer.PrinterIndex := iPrinterIndex;
  iPrinterName := Printer.Printers.Strings[Printer.PrinterIndex];
  ImageEnView1.IO.DoPrintPreviewDialog(iedtDialog, 'Image', False, 'Print Preview- ' + iPrinterName);
end;

procedure TformViewPhotographs.SpeedButtonPrintSingleClick(Sender: TObject);
var
  iPrinterIndex: Integer;
  tempPrinterName: string;
begin
  iPrinterIndex := -1;      // The assumption is that the default printer.PrinterIndex = -1;
  Printer.PrinterIndex := iPrinterIndex;
  tempPrinterName := Printer.Printers.Strings[Printer.PrinterIndex];
 
 ImageEnView1.io.DoPrintPreviewDialog(iedtDialog, 'Patient - ' + DataPatients.adsTablePatients.FieldByName('FirstName').AsString
 + ' ' + DataPatients.adsTablePatients.FieldByName('LastName').AsWideString,                                                False, 'Print Preview With Default Printer - ' + tempPrinterName);

end;