Author: Jonas Bilinkevicius

How to set the PixelsPerInch property of a TPrinter

Answer:

When changing printers, be aware that fontsizes may not always scale properly. To 
ensure proper scaling, set the PixelsPerInch property of the font after changing 
the printer index property. Be sure not to make the change until you have started 
the print job.

Here are two examples:

1   uses
2     Printers;
3   
4   var
5     MyFile: TextFile;
6   begin
7     Printer.PrinterIndex := 2;
8     AssignPrn(MyFile);
9     Rewrite(MyFile);
10    Printer.Canvas.Font.Name := 'Courier New';
11    Printer.Canvas.Font.Style := [fsBold];
12    Printer.Canvas.Font.PixelsPerInch := GetDeviceCaps(Printer.Canvas.Handle,
13      LOGPIXELSY);
14    Writeln(MyFile, 'Print this text');
15    System.CloseFile(MyFile);
16  end;
17  
18  uses
19    Printers;
20  
21  begin
22    Printer.PrinterIndex := 2;
23    Printer.BeginDoc;
24    Printer.Canvas.Font.Name := 'Courier New';
25    Printer.Canvas.Font.Style := [fsBold];
26    Printer.Canvas.Font.PixelsPerInch := GetDeviceCaps(Printer.Canvas.Handle,
27      LOGPIXELSY);
28    Printer.Canvas.Textout(10, 10, 'Print this text');
29    Printer.EndDoc;
30  end;