En esto no te puedo ayudar... No se que hace internamente TRichEdit.Print.
Supongo que se podrá hacer algo con TPrinter.PageHeight y TPrinter.PageWidth.
Del help de Delphi 6:
The VCL TPrinter object encapsulates details of Windows printers. To get a list of installed and available printers, use the Printers property. The CLX TPrinter object is a paint device that paints on a printer. It generates postscript and sends that to lpr, lp, or another print command.
Both printer objects use a TCanvas (which is identical to the form's TCanvas) which means that anything that can be drawn on a form can be printed as well. To print an image, call the BeginDoc method followed by whatever canvas graphics you want to print (including text through the TextOut method) and send the job to the printer by calling the EndDoc method.
This example uses a button and a memo on a form. When the user clicks the button, the content of the memo is printed with a 200-pixel border around the page.
To run this example successfully, add Printers to your uses clause.
Código Delphi
[-]
procedure TForm1.Button1Click(Sender: TObject);
var
r: TRect;
i: Integer;
begin
with Printer do
begin
r := Rect(200,200,(Pagewidth - 200),(PageHeight - 200));
BeginDoc;
for i := 0 to Memo1.Lines.Count do
Canvas.TextOut(200,200 + (i * Canvas.TextHeight(Memo1.Lines.Strings[i])),Memo1.Lines.Strings[i]);
Canvas.Brush.Color := clBlack;
Canvas.FrameRect(r);
EndDoc;
end;
end;
Además de esto (imprimir directamente), supongo que te servirá mirar un poco el QuickReport.
Es cuestion de agregar una banda de impresion y repetirla tantas veces como desees.