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EMF Printer Spool File Viewer

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23 Apr 2014CPOL3 min read 829.7K   25.3K   92   181
A viewer application for EMF format spool files

What is an EMF Spool File?

When an application sends pages to a printer, they are held in an intermediary file which the application can write to and the printer driver can read from simultaneously. This speeds up the print process as control can return to the application before the printer has finished printing the document.

Usually, this spool file is held in the raw printer page definition language (which could be PCL, PostScript or one of many other options) but in Windows NT, 2000, XP and 2003, it is possible to make the spooler use a different, more device independent format known as an EMF spool file.

The file layout of an EMF spool file is not officially documented by Microsoft, but the newly released documentation reveals that it is a series of enhanced metafile records (one for each page) and a number of other record types which are specific to the business of printing these pages.

The EMF Spool File Record Types

The spool file is composed of the following record types:

Private Enum SpoolerRecordTypes
    SRT_EOF = &H0            ' // int32 zero
    SRT_RESERVED_1 = &H1     '*  1                               */
    SRT_FONTDATA = &H2       '  2 Font Data                      */
    SRT_DEVMODE = &H3        '  3 DevMode                        */
    SRT_FONT2 = &H4          '4 Font Data                        */
    SRT_RESERVED_5 = &H5     ' 5                                 */
    SRT_FONT_MM = &H6        ' 6 Font Data (Multiple Master)     */
    SRT_FONT_SUB1 = &H7      '   7 Font Data (SubsetFont 1)      */
    SRT_FONT_SUB2 = &H8      '   8 Font Data (SubsetFont 2)
    SRT_RESERVED_9 = &H9
    SRT_UNKNOWN = &H10       ' // int unknown...
    SRT_PAGE = &HC           ' 12  Enhanced Meta File (EMF)       */
    SRT_EOPAGE1 = &HD        ' 13  EndOfPage                      */
    SRT_EOPAGE2 = &HE        ' 14  EndOfPage                      */
    SRT_EXT_FONT = &HF       ' 15  Ext Font Data                  */
    SRT_EXT_FONT2 = &H10     ' 16  Ext Font Data                  */
    SRT_EXT_FONT_MM = &H11   ' 17  Ext Font Data (Multiple Master)
    SRT_EXT_FONT_SUB1 = &H12 ' 18  Ext Font Data (SubsetFont 1)   */
    SRT_EXT_FONT_SUB2 = &H13 '* 19  Ext Font Data (SubsetFont 2)  */
    SRT_EXT_PAGE = &H14      ' 20  Enhanced Meta File?
End Enum

Of these, the most important record types are:


This record contains a Windows standard enhanced metafile, consisting of an EMF header and one or more EMF graphics record structures. The EMF header record gives you the dimensions of the boundary rectangle (the area inside the print margins), the number of graphics records that make up the page, and the file size of this single EMF page.


This record contains the device settings that apply to the rest of the pages in the document (or until another DEVMODE record is encountered that overrides it). The DEVMODE structure holds details such as the number of copies, the page orientation (landscape versus portrait), the paper size and paper source, and so on.


This signifies the end of the spool file records.

Using the EMF Spoolfile Viewer

To view an EMF spool file, select the menu File -> Open. A dialog box will appear to allow you to browse to the spool file (extension .spl). These are typically held in your $winnt$\System32\spool\ directory. (I have included some samples with this application code as well.)

The viewer allows you to go to a particular page, zoom in and out, and even print the spool file using the following menu options:

  • File
    • Open - Brings up a dialog box to find and open EMF spool files
    • Print - Allows you to reprint the currently open EMF spool file
    • Properties - Brings up a dialog box listing the print file properties
    • Exit - Quits the application
  • Pages
    • First Page - Goes to the beginning of the document
    • Previous Page - Goes back one page
    • Next Page - Goes to the next page
    • Last Page - Goes to the end of the document
    • Goto - Goes directly to the selected page
    • Properties = Brings up a dialog with the properties of this page
  • View
    • Zoom in enlarges the preview
    • Zoom out reduces the size of the preview

Uses for EMF Spoolfiles

Since pretty much every application has a print function, the EMF spool file can serve as a quick and dirty portable document format (though much less featured than a PDF). Thus if you have an application and you want to send a file to someone who doesn't have that application to view, you simply use the application's print function and send them the spool file.

In addition, knowing the structure of the spool file means that it is possible to parse the file to extract information from it. You might want to extract just the text from a printed document for archival purposes, and you can do this by parsing the file and extracting the EMR_EXTTEXTOUTA and EMR_EXTTEXTOUTW records.


The source code in this application draws heavily on the work of Feng Yuan and Christophe Lindemann as well as numerous others on the various forums and news groups.

Portions of this article are based on These portions are subject to the GNU Free Documentation License and are copyright © 2003-2005 Free Software Foundation, Inc.


  • 21st August, 2006: Code updated to .NET 2.0 and page navigation improved


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Written By
Software Developer
Ireland Ireland
C# / SQL Server developer
Microsoft MVP (Azure) 2017
Microsoft MVP (Visual Basic) 2006, 2007

Comments and Discussions

Questionspoolfilereadertest.exe alert Pin
Member 1584307624-Nov-22 12:56
Member 1584307624-Nov-22 12:56 
AnswerRe: spoolfilereadertest.exe alert Pin
Gomesh_5-Dec-22 8:08
Gomesh_5-Dec-22 8:08 
QuestionThank you very much, this helps me! Pin
bobsel8-Mar-21 1:03
bobsel8-Mar-21 1:03 
Questionnothing happens when I try to open a file Pin
Member 1284601428-Sep-19 1:03
Member 1284601428-Sep-19 1:03 
QuestionRead text from spl file Pin
cuong thieu12-Nov-18 19:54
cuong thieu12-Nov-18 19:54 
AnswerRe: Read text from spl file Pin
Member 1343235026-Jul-20 17:25
Member 1343235026-Jul-20 17:25 
QuestionCan write content to .txt file? Pin
Member 1303241530-Jun-17 15:57
Member 1303241530-Jun-17 15:57 
QuestionLarge files Pin
Member 1300267315-Mar-17 1:15
Member 1300267315-Mar-17 1:15 
AnswerRe: Large files Pin
Duncan Edwards Jones15-Mar-17 2:38
professionalDuncan Edwards Jones15-Mar-17 2:38 
QuestionSHD File? How do you read it? Pin
Member 126225476-Jul-16 23:56
Member 126225476-Jul-16 23:56 
AnswerRe: SHD File? How do you read it? Pin
Duncan Edwards Jones7-Jul-16 0:21
professionalDuncan Edwards Jones7-Jul-16 0:21 
QuestionEMF and usernames Pin
Николай Каретников18-Jan-16 9:29
Николай Каретников18-Jan-16 9:29 
AnswerRe: EMF and usernames Pin
Duncan Edwards Jones18-Jan-16 10:13
professionalDuncan Edwards Jones18-Jan-16 10:13 
Questionthanks Pin
Member 114578476-Oct-15 10:51
Member 114578476-Oct-15 10:51 
QuestionEMF extraction Pin
Member 115950069-Apr-15 12:35
Member 115950069-Apr-15 12:35 
Questionno exe Pin
Member 114840261-Mar-15 5:29
Member 114840261-Mar-15 5:29 
AnswerRe: no exe Pin
Duncan Edwards Jones28-Jul-15 23:31
professionalDuncan Edwards Jones28-Jul-15 23:31 
GeneralRe: no exe Pin
Member 1328370428-Jun-17 12:34
Member 1328370428-Jun-17 12:34 
QuestionCannot download file Pin
lally0672-Feb-15 20:36
lally0672-Feb-15 20:36 
AnswerRe: Cannot download file Pin
Duncan Edwards Jones2-Feb-15 21:05
professionalDuncan Edwards Jones2-Feb-15 21:05 
QuestionNumber of copies in spl file Pin
Member 1048979220-Jan-15 1:53
professionalMember 1048979220-Jan-15 1:53 
AnswerRe: Number of copies in spl file Pin
Duncan Edwards Jones20-Jan-15 2:54
professionalDuncan Edwards Jones20-Jan-15 2:54 
GeneralRe: Number of copies in spl file Pin
Member 1048979220-Jan-15 17:52
professionalMember 1048979220-Jan-15 17:52 
GeneralRe: Number of copies in spl file Pin
Duncan Edwards Jones21-Jan-15 9:04
professionalDuncan Edwards Jones21-Jan-15 9:04 
GeneralRe: Number of copies in spl file Pin
Member 1048979221-Jan-15 18:13
professionalMember 1048979221-Jan-15 18:13 

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