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                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                 Schedule 13D/A


          Under the Securities Exchange Act of 1934 (Amendment No. 4)


                            DUPONT PHOTOMASKS, INC.

          Common Stock, par value $0.01 (Title of Class of Securities)

                                  26613X 10 1
                                 (CUSIP Number)

                             Peter C. Mester, Esq.
                      E.I. du Pont de Nemours and Company
                                1007 Market St.
                              Wilmington, DE 19898
                                 (302) 774-6445
                 (Name, Address and Telephone Number of Person
               Authorized to Receive Notices and Communications)


                                 April 30, 2001
                      (Date of Event which Requires Filing
                               of this Statement)


If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g),
check the following box [ ].

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
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CUSIP    NUMBER: 26613X 10 1                                  PAGE 2 OF 11 PAGES



--------------------------------------------------------------------------------
1)   Names of Reporting Persons; I.R.S. Identification Nos. (entities only)

             E.I. du Pont de Nemours and Company; 51-0014090
--------------------------------------------------------------------------------
2)   Check the Appropriate Box if a Member of a Group (See Instructions)

     (a)

     (b)
--------------------------------------------------------------------------------
3)   SEC Use Only
--------------------------------------------------------------------------------
4)   Source of Funds (See Instructions)
--------------------------------------------------------------------------------
5)   Check if Disclosure of Legal Proceedings is Required Pursuant to Items 2(d)
     or 2(e)
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6)       Citizenship or Place of Organization                           Delaware
--------------------------------------------------------------------------------

   Number of                        7)      Sole Voting Power          3,693,272
    Shares                 -----------------------------------------------------
 Beneficially
   Owned by                         8)      Shared Voting Power
Each Reporting             -----------------------------------------------------
 Person With
                                    9)      Sole Dispositive Power     3,693,272
                           -----------------------------------------------------

                                    10)     Shared Dispositive Power
                           -----------------------------------------------------

11)      Aggregate Amount Beneficially
         Owned by Each Reporting Person                                3,693,272

         -----------------------------------------------------------------------
12)      Check if the Aggregate Amount in Row (11)
         Excludes Certain Shares (See Instructions)
--------------------------------------------------------------------------------

13)      Percent of Class Represented by Amount in Row (11)               21.24%

--------------------------------------------------------------------------------
14)      Type of Reporting Persons (See Instructions)                         CO
--------------------------------------------------------------------------------


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CUSIP    NUMBER: 26613X 10 1                                  PAGE 3 OF 11 PAGES



--------------------------------------------------------------------------------
1)   Names of Reporting Persons; I.R.S. Identification Nos. (entities only)

           DuPont Chemical and Energy Corporation; 51-0313062
--------------------------------------------------------------------------------
2)   Check the Appropriate Box if a Member of a Group (See Instructions)

     (a)

     (b)
--------------------------------------------------------------------------------
3)   SEC Use Only
--------------------------------------------------------------------------------
4)   Source of Funds (See Instructions)
--------------------------------------------------------------------------------
5)   Check if Disclosure of Legal Proceedings is Required Pursuant to Items 2(d)
     or 2(e)
--------------------------------------------------------------------------------
6)       Citizenship or Place of Organization                           Delaware
--------------------------------------------------------------------------------

   Number of              7)       Sole Voting Power                   3,693,272
    Shares        --------------------------------------------------------------
 Beneficially
   Owned by               8)       Shared Voting Power
Each Reporting    --------------------------------------------------------------
 Person With
                          9)       Sole Dispositive Power              3,693,272
                  --------------------------------------------------------------

                          10)      Shared Dispositive Power
                  --------------------------------------------------------------

11)      Aggregate Amount Beneficially
         Owned by Each Reporting Person                                3,693,272

--------------------------------------------------------------------------------
12)      Check if the Aggregate Amount in Row (11)
         Excludes Certain Shares (See Instructions)
--------------------------------------------------------------------------------

13)      Percent of Class Represented by Amount in Row (11)               21.24%

--------------------------------------------------------------------------------
14)      Type of Reporting Persons (See Instructions)                         CO
--------------------------------------------------------------------------------




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CUSIP    NUMBER: 26613X 10 1                                  PAGE 4 OF 11 PAGES




         This Amendment No. 4 to Schedule 13D is filed pursuant to Rule 13d-1 of
the Rules and Regulations under the Securities Exchange Act of 1934, as amended
(the "Exchange Act") by E. I. du Pont de Nemours and Company, a Delaware
corporation ("DuPont") and by Du Pont Chemical and Energy Operations, Inc., a
Delaware corporation and wholly owned subsidiary of DuPont ("DCEO"), with
respect to the common stock of DuPont Photomasks, Inc., a Delaware corporation
("DPI" or the "Issuer"):


ITEM 1.       SECURITY AND ISSUER.

              This Schedule 13D relates to the Common Stock, par value $0.01 per
share ("Common Stock"), of DPI. The principal executive offices of DPI are
located at 131 Old Settlers Boulevard, Round Rock, Texas 78664.

ITEM 2.       IDENTITY AND BACKGROUND.

              This Schedule 13D is filed by DuPont and by DCEO. The principal
executive offices of both corporations are located at 1007 Market Street,
Wilmington, Delaware 19898.

              DuPont was founded in 1802 and was incorporated in Delaware in
1915. DuPont is a world leader in science and technology in a range of
disciplines including high-performance materials, specialty chemicals,
pharmaceuticals and biotechnology. DuPont operates globally through some 20
strategic business units. Within the strategic business units, approximately 80
businesses manufacture and sell a wide range of products to many different
markets, including the transportation, textile, construction, automotive,
agricultural and hybrid seeds, nutrition and health, pharmaceuticals, packaging
and electronics markets.

              DuPont's strategic business units have been aggregated into nine
reportable segments Agriculture & Nutrition, Nylon Enterprise, Performance
Coatings & Polymers, Pharmaceuticals, Pigments & Chemicals, Pioneer Hi-Bred
International, Inc., Polyester Enterprise, Specialty Fibers and Specialty
Polymers.




              DCEO was incorporated in Delaware in 1988 and is limited by its
certificate of incorporation to the making, maintenance and management of its
intangible investments and the collection and distribution of the income from
such investments. DCEO is a wholly owned subsidiary of DuPont.

              Information concerning the directors and executive officers of
DuPont and DCEO is contained in Schedule A attached hereto.

              During the last five years, none of DuPont or DCEO nor, to the
best knowledge of DuPont and DCEO, any director or executive officer of DuPont
or DCEO has been (i) convicted in a criminal



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CUSIP    NUMBER: 26613X 10 1                                  PAGE 5 OF 11 PAGES



proceeding or (ii) a party to a civil proceeding of a judicial or administrative
body of competent jurisdiction and as a result of such proceeding has been or is
subject to a judgment, decree or final order enjoining future violations of, or
prohibiting or mandating activities subject to, federal or state securities laws
or finding any violation with respect to such laws.

ITEM 3.       SOURCE AND AMOUNT OF FUNDS OTHER CONSIDERATION.

              Not applicable.

ITEM 4.       PURPOSE OF TRANSACTION.


              On April 30, 2001, DuPont sold an aggregate of 2,000,000 shares of
the Issuer's Common Stock pursuant to Rule 144 under the Securities
Act of 1933, as amended. Prior thereto, during November 2000, DuPont sold an
aggregate of 375,000 shares of the Issuer's Common Stock pursuant to sales under
Rule 144 under the Securities Act of 1933, as amended. Prior thereto, on July
24, 2000, DuPont sold an aggregate of 1,777,778 shares of the Issuer's Common
Stock pursuant to an underwritten public offering registered pursuant to the
Securities Act of 1933, as amended. During May 2000, DuPont sold an aggregate of
55,000 shares of the Issuer's Common Stock pursuant to sales under Rule 144
under the Securities Act of 1933, as amended, for the purpose of allowing DuPont
to obtain a tax benefit associated with a loss from an earlier sale of the
Issuer's interest in DuPont Korea Ltd. to DuPont, which tax benefit would have
expired on June 30, 2000. During March 1999, DuPont sold an aggregate of
2,100,000 shares of the Issuer's common stock pursuant to a registered
underwritten public offering. During September 1999, DuPont sold an aggregate of
498,950 shares of the Issuer's common stock pursuant to sales under Rule 144.


              (a) DuPont has advised the Issuer that it expects to reduce its
ownership interest in the Issuer over time, subject to prevailing market and
other conditions. Consistent with this advice, DuPont made the sales described
above and expects to continue to dispose of its holdings from time to time as
conditions warrant.

              (b-j) Not applicable.

ITEM 5.       INTEREST IN SECURITIES OF THE ISSUER.


              (a) and (b) As of May 1, 2001, DuPont directly owns
3,693,272 shares of Common Stock of the Issuer. Such shares constitute
approximately 21.24% percent of the total number of shares of Common Stock
outstanding as of such date. No director or executive officer of DuPont or DCEO
beneficially owns any shares of Common Stock of the Issuer.



              (c) On April 30, 2001, DuPont sold an aggregate of
2,000,000 shares of the Issuer's Common Stock pursuant to sales under Rule 144
under the Securities Act of 1933, as amended, reducing DuPont's ownership
interest in the Issuer's Common Stock from 5,693,272 to 3,693,272 shares.


              (d) No person other than DCEO and DuPont has the right to receive
or the power to direct receipt of dividends from, or the proceeds from the sale
of, the Common Stock of the Issuer.

              (e) Not applicable.



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CUSIP    NUMBER: 26613X 10 1                                  PAGE 6 OF 11 PAGES



ITEM 6.       CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH
              RESPECT TO SECURITIES OF THE ISSUER.

              DCEO has entered into a Registration Rights Agreement dated
December 31, 1995 (the "Registration Rights Agreement") with the Issuer under
which it and its assignees will be entitled to certain rights with respect to
the registration under the Securities Act of shares of Common Stock they hold.
Subject to certain limitations (including a minimum registration of over
1,000,000 shares), each of DCEO and its assignees has the right to require the
Issuer to register the sale of all or part of the shares it holds under the
Securities Act (a "demand registration"). DCEO and its assignees, in the
aggregate, initially were entitled to request up to five demand registrations,
four of which remain available, and each is also entitled to include the shares
of Common Stock it holds in a registered offering of securities by the Issuer
for its own account, subject to certain conditions and restrictions. The Issuer
will pay all expenses associated with a registration of shares of Common Stock
by DCEO and its assignees pursuant to the Registration Rights Agreement, other
than underwriting discounts and commissions, their out-of-pocket expenses or
underwriters' counsel fees and disbursements, if any, relating to such shares.
In addition, the Registration Rights Agreement contains certain indemnification
provisions (i) by the Issuer for the benefit of DCEO and its assignees as well
as any potential underwriter and (ii) by DCEO and its assignees for the benefit
of the Issuer and related persons. DCEO and its assignees may transfer their
registration rights under the Registration Rights Agreement without the prior
approval of the Issuer. The Registration Rights Agreement also provides that
while DCEO owns 50% or more of the Issuer's Common Stock, the Issuer may not
grant registration rights to any other person without DCEO's prior consent.
              DuPont is the guarantor of $100,000,000 principal amount of the
Issuer's convertible subordinated notes due 2004, which notes were issued
pursuant to a registered public offering which was consummated on July 24,
2000.
              Except for the foregoing agreements, there are no other contracts,
arrangements, understandings or relationships (legal or otherwise) among the
persons named in Item 2 and between such persons and any person with respect to
any securities of the Issuer.

ITEM 7.       MATERIAL TO BE FILED AS EXHIBITS.

              The following agreement is filed as an exhibit to this
Schedule 13D.


              A. Agreement dated May 1, 2001, between DuPont and DCEO pursuant
to which both agree that this Schedule is filed on behalf of both of them.




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CUSIP    NUMBER: 26613X 10 1                                  PAGE 7 OF 11 PAGES



                                    SIGNATURE


              After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this Statement is true,
complete and correct.


                                     E.I. DU PONT DE NEMOURS AND COMPANY


                                     By:     /s/ S.M. STALNECKER
                                             Susan M. Stalnecker
                                             Vice President and Treasurer


                                     DUPONT CHEMICAL AND ENERGY
                                     OPERATIONS, INC.


                                     By:     /s/ S.M. STALNECKER
                                             Susan M. Stalnecker
                                             President



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CUSIP    NUMBER: 26613X 10 1                                  PAGE 8 OF 11 PAGES



                                   SCHEDULE A

         1. Set forth below are the name and present principal occupation or
employment with E. I. du Pont de Nemours and Company of each director and
executive officer. The address of each of the persons listed is c/o DuPont at
1007 Market Street, Wilmington, Delaware 19898. With the exception of Messrs.
Belda, Lindahl and Naitoh, who are citizens of Brazil, Sweden and Japan,
respectively, each person listed below is a citizen of the United States of
America.

         DIRECTORS:

         Alain J. P. Belda            President and Chief Executive Officer,
                                      Alcoa Inc.

         Curtis J. Crawford           President and Chief Executive Officer
                                      ZiLOG, Inc.

         Louisa C. Duemling           Director

         Edward B. du Pont            Director

         Charles O. Holliday, Jr.     Chairman and Chief Executive Officer

         Deborah C. Hopkins           Chief Financial Officer and Executive
                                      Vice President, Lucent Technologies

         Louis D. Juliber             Chief Operating Officer,
                                      Colgate-Palmolive Company

         Goran Lindahl                President and Chief Executive Officer,
                                      ABB Ltd.

         Masahisa Naitoh              Executive Vice President,
                                      ITOCHU Corporation

         William K. Reilly            President and Chief Executive Officer,
                                      Aqua International Partners, L.P.

         H. Rodney Sharp, III         Director

         Charles M. Vest              President,
                                      Massachusetts Institute of Technology






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CUSIP    NUMBER: 26613X 10 1                                  PAGE 9 OF 11 PAGES



         EXECUTIVE OFFICERS:

         Chairman, Board of Directors
         C. O. Holliday, Jr.

         Chief Executive Officer
         C. O. Holliday, Jr.

         Executive Vice President
         R. R. Goodmanson


         Senior Vice Presidents
         T. M. Connelly
         S. J. Mobley
         G. M. Pfeiffer




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CUSIP    NUMBER: 26613X 10 1                                 PAGE 10 OF 11 PAGES



                2. Set forth below are the name and principal occupation or
employment with DuPont Chemical and Energy Operations, Inc. of each director and
executive officer. The address of each of the persons listed is c/o DuPont at
1007 Market Street, Wilmington, Delaware 19898. Each person listed below is a
citizen of the United States.

         NAME AND ADDRESS               POSITION

         Susan M. Stalnecker            President and Director



         Joseph A. Girardi              Vice President, Treasurer and Director


         A. Lloyd Adams                 Vice President, Assistant Treasurer
                                        and Director

         Loriann Lea                    Secretary



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