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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
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                                   SCHEDULE TO
                                 (RULE 14d-100)

            TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                                (Amendment No. 6)

                                 DTM CORPORATION
                       (Name of Subject Company (Issuer))

                                TIGER DEALS, INC.

                             3D SYSTEMS CORPORATION
                                   (Offerors)

                    COMMON STOCK, $0.0002 PAR VALUE PER SHARE
                         (Title of Class of Securities)

                                   23333 L 103
                      (CUSIP Number of Class of Securities)

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                                                       COPY TO:
          E. JAMES SELZER
    CHIEF FINANCIAL OFFICER AND                  JULIE M. KAUFER, ESQ.
      VICE PRESIDENT, FINANCE          AKIN, GUMP, STRAUSS, HAUER & FELD, L.L.P.
       3D SYSTEMS CORPORATION                   2029 CENTURY PARK EAST
         26081 AVENUE HALL                            SUITE 2400
     VALENCIA, CALIFORNIA 91355              LOS ANGELES, CALIFORNIA 90067
           (661) 295-5600                           (310) 229-1000


(Name, address, and telephone number of persons authorized to receive notices
                and communications on behalf of filing persons)

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                            CALCULATION OF FILING FEE
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       Transaction valuation*                          Amount of filing fee**
            $46,971,196                                        $9,395
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*       Estimated for purposes of calculating the filing fee only. Calculated
        based on the product of $5.80, the per share tender offer price for all
        the outstanding shares of common stock, par value $0.0002 per share, of
        DTM Corporation (the "Common Shares"), multiplied by 8,098,482 (which
        includes 977,493 shares issuable pursuant to the exercise of outstanding
        stock options).

**      The amount of the filing fee, calculated in accordance with Rule 0-11(d)
        of the Securities Exchange Act of 1934, as amended, equals 1/50th of one
        percent of the aggregate value of cash offered by Tiger Deals, Inc. for
        such number of Common Shares.

[X]     Check the box if any part of the fee is offset as provided by Rule
        0-11(a)(2) and identify the filing with which the offsetting fee was
        previously paid. Identify the previous filing by registration statement
        number, or the Form or Schedule and the date of its filing.



                                                              
        Amount Previously Paid......$9,395                       Filing Party......Tiger Deals, Inc. and
                                                                                   3D Systems Corporation
        Form or Reg. No.............Schedule TO                  Date Filed........April 30, 2001
                                    Amend. No. 1 to Schedule TO                    May 16, 2001


[]      Check the box if the filing relates solely to preliminary communications
        made before the commencement of a tender offer.

        [X]    third-party tender offer subject to Rule 14d-1.

        [ ]    issuer tender offer subject to Rule 13e-4.

        [ ]    going-private transaction subject to Rule 13e-3.

        [ ]    amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer: [ ]

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        This Amendment No. 6 amends and supplements the Tender Offer Statement
on Schedule TO filed with the SEC on April 30, 2001, as amended and supplemented
by Amendment No. 1 filed with the SEC on May 16, 2001, Amendment No. 2 filed
with the SEC on May 22, 2001, Amendment No. 3 filed with the SEC on May 25,
2001, Amendment No. 4 filed with the SEC on June 7, 2001 and Amendment No. 5
filed with the SEC on June 19, 2001, relating to the offer to purchase by Tiger
Deals, Inc., or "Offeror," a Delaware corporation and an indirect wholly-owned
subsidiary of 3D Systems Corporation, or "Parent," a Delaware corporation, all
of the outstanding shares of common stock, par value $0.0002 per share, of DTM
Corporation, or the "Company," a Texas corporation, at a purchase price of $5.80
per share, net to the seller in cash, without interest and less any required
withholding taxes, upon the terms and subject to the conditions set forth in the
"Offer to Purchase," dated as of April 30, 2001, the "Amendment and Supplement
to Offer to Purchase," dated as of May 15, 2001, and in the related Letter of
Transmittal. Copies of the Offer to Purchase, Amendment and Supplement to Offer
to Purchase and Letter of Transmittal were filed as Exhibits (a)(1)(i),
(a)(1)(ix) and (a)(1)(ii), respectively, to the Schedule TO, as amended.
Capitalized terms used herein but not otherwise defined have the meanings
ascribed to those terms in the Offer to Purchase.

        The information in the Schedule TO, as amended, is hereby expressly
incorporated herein by reference in response to all the items of this Amendment
No. 6, except as otherwise set forth below. You should read this amendment
together with the Schedule TO we filed on April 30, 2001, the Amendment No. 1 to
Schedule TO we filed on May 16, 2001, the Amendment No. 2 to Schedule TO we
filed on May 22, 2001, the Amendment No. 3 to Schedule TO we filed on May 25,
2001, the Amendment No. 4 to Schedule TO we filed on June 7, 2001 and the
Amendment No. 5 to Schedule TO we filed on June 19, 2001.

ITEM 1. SUMMARY TERM SHEET.

        Item 1 of Schedule TO is hereby amended and supplemented by including
the following:

        On July 5, 2001, we extended the offer until 12:00 midnight, New York
City time, on Tuesday, July 24, 2001. The full text of the joint press release
we issued with DTM on July 5, 2001 announcing the extension of the offer is
filed as Exhibit (a)(1)(xiv) hereto.

ITEM 4. TERMS OF THE TRANSACTION.

        Item 4 of Schedule TO is hereby amended and supplemented by including
the following:

        On July 5, 2001, we extended the offer until 12:00 midnight, New York
City time, on Tuesday, July 24, 2001. The full text of the joint press release
we issued with DTM on July 5, 2001 announcing the extension of the offer is
filed as Exhibit (a)(1)(xiv) hereto.

ITEM 11. ADDITIONAL INFORMATION.

        Item 11 of Schedule TO is hereby amended and supplemented by including
the following:

        On June 20, 2001, we executed a letter agreement with DTM pursuant to
which DTM agreed not to exercise its right to terminate the merger agreement
under Section 9.1(b)(1)(y) of the merger agreement prior to midnight New York
City time on July 10, 2001, in order to induce us to extend the offer to that
date. DTM otherwise would have been entitled to exercise this termination right
commencing on July 5, 2001, the date which is 65 days following the commencement
of the offer. This letter agreement is filed as Exhibit(a)(5)(i) hereto and is
incorporated herein by reference.

        On July 5, 2001, we extended the offer until 12:00 midnight, New York
City time, on Tuesday, July 24, 2001. In order to induce us to extend the offer
to that date, DTM executed a letter agreement with us pursuant to which DTM
agreed not to exercise its right to terminate the merger agreement under Section
9.1(b)(1)(y) of the merger agreement prior to midnight New York City time on
July 24, 2001. DTM would otherwise have been entitled to exercise this right
commencing on July 11, 2001. This letter agreement and the joint press release
announcing the extension of the offer is filed hereto and incorporated herein by
reference as Exhibit(a)(5)(ii) and (a)(1)(xiv), respectively.


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ITEM 12. EXHIBITS.

                                  EXHIBIT INDEX



EXHIBIT
NUMBER                DESCRIPTION
-------               -----------
                   
(a)(1)(i)             Offer to Purchase, dated as of April 30, 2001.(1)

(a)(1)(ii)            Letter of Transmittal for Common Stock.(1)

(a)(1)(iii)           Notice of Guaranteed Delivery for Common Stock.(1)

(a)(1)(iv)            Letter to Brokers, Dealers, Commercial Banks, Trust
                      Companies and Other Nominees.(1)

(a)(1)(v)             Letter to Clients from Brokers, Dealers, Commercial Banks,
                      Trust Companies and Other Nominees.(1)

(a)(1)(vi)            Guidelines for Certification of Taxpayer Identification
                      Number on Substitute Form W-9.(1)

(a)(1)(vii)           Text of Joint Press Release issued by the Company and
                      Parent on April 3, 2001 (incorporated by reference to
                      Exhibit 99.1 to Parent's Form 8-K filed April 10, 2001).

(a)(1)(viii)          Summary advertisement published in The Wall Street Journal
                      on April 30, 2001.(1)

(a)(1)(ix)            Amendment and Supplement to Offer to Purchase, dated as of
                      May 15, 2001.(2)

(a)(1)(x)             Text of Press Release issued by Parent on May 21, 2001.(3)

(a)(1)(xi)            Text of Press Release issued by Parent on May 25, 2001.(4)

(a)(1)(xii)           Text of Joint Press Release issued by the Company and
                      Parent on June 6, 2001.(5)

(a)(1)(xiii)          Text of Joint Press Release issued by the Company and
                      Parent on June 18, 2001.(6)

(a)(1)(xiv)           Text of Joint Press Release issued by the Company and
                      Parent on July 5, 2001.

(a)(2)                Not applicable.

(a)(3)                Not applicable.

(a)(4)                Not applicable.

(a)(5)(i)             Letter Agreement, dated as of June 20, 2001, by and among
                      the Company, Parent and Offeror.

(a)(5)(ii)            Letter Agreement, dated as of July 5, 2001, by and among
                      the Company, Parent and Offeror.

(b)                   Commitment Letter, dated as of April 24, 2001, by U.S.
                      Bank National Association and Parent.(1)

(b)(1)                Loan and Security Agreement, dated as of May 21, 2001, by
                      and among U.S. Bank National Association, Parent and other
                      signatories.(3)

(d)(1)                Agreement and Plan of Merger, dated as of April 2, 2001,
                      by and among the Company, Parent and Offeror (incorporated
                      by reference to Exhibit 99.2 to Parent's Schedule TO-C
                      filed April 3, 2001).

(d)(2)                Amendment No. 1 to Agreement and Plan of Merger, dated as
                      of May 15, 2001, by and among the Company, Parent and
                      Offeror.(2)

(d)(3)                Form of Tender and Voting Agreement, dated as of April 2,
                      2001, by and among Parent, Offeror and certain
                      shareholders of the Company



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                      (incorporated by reference to Exhibit 99.3 to Parent's
                      Schedule TO-C filed April 3, 2001).

(g)                   None.

(h)                   None.


(1)  Previously filed on Schedule TO filed with the SEC on April 30, 2001.

(2)  Previously filed on Amendment No. 1 to Schedule TO filed with the SEC on
     May 16, 2001.

(3)  Previously filed on Amendment No. 2 to Schedule TO filed with the SEC on
     May 22, 2001.

(4)  Previously filed on Amendment No. 3 to Schedule TO filed with the SEC on
     May 25, 2001.

(5)  Previously filed on Amendment No. 4 to Schedule TO filed with the SEC on
     June 7, 2001.

(6)  Previously filed on Amendment No. 5 to Schedule TO filed with the SEC on
     June 19, 2001.


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                                    SIGNATURE

        After due 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.

Dated:  July 6, 2001             TIGER DEALS, INC.



                                 BY:    /S/ E. James Selzer
                                        ----------------------------------------
                                        Name:  E. James Selzer
                                        Title: Chief Financial Officer and
                                               Vice President, Finance


        After due 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.

Dated:  July 6, 2001             3D SYSTEMS CORPORATION



                                 BY:     /S/ E. James Selzer
                                        ----------------------------------------
                                         Name:  E. James Selzer
                                         Title: Chief Financial Officer and
                                                Vice President, Finance



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                                  EXHIBIT INDEX



EXHIBIT
NUMBER                DESCRIPTION
-------               -----------
                   
(a)(1)(i)             Offer to Purchase, dated as of April 30, 2001.(1)

(a)(1)(ii)            Letter of Transmittal for Common Stock.(1)

(a)(1)(iii)           Notice of Guaranteed Delivery for Common Stock.(1)

(a)(1)(iv)            Letter to Brokers, Dealers, Commercial Banks, Trust
                      Companies and Other Nominees.(1)

(a)(1)(v)             Letter to Clients from Brokers, Dealers, Commercial Banks,
                      Trust Companies and Other Nominees.(1)

(a)(1)(vi)            Guidelines for Certification of Taxpayer Identification
                      Number on Substitute Form W-9.(1)

(a)(1)(vii)           Text of Joint Press Release issued by the Company and
                      Parent on April 3, 2001 (incorporated by reference to
                      Exhibit 99.1 to Parent's Form 8-K filed April 10, 2001).

(a)(1)(viii)          Summary advertisement published in The Wall Street Journal
                      on April 30, 2001.(1)

(a)(1)(ix)            Amendment and Supplement to Offer to Purchase, dated as of
                      May 15, 2001.(2)

(a)(1)(x)             Text of Press Release issued by Parent on May 21, 2001.(3)

(a)(1)(xi)            Text of Press Release issued by Parent on May 25, 2001.(4)

(a)(1)(xii)           Text of Joint Press Release issued by the Company and
                      Parent on June 6, 2001.(5)

(a)(1)(xiii)          Text of Joint Press Release issued by the Company and
                      Parent on June 18, 2001.(6)

(a)(1)(xiv)           Text of Joint Press Release issued by the Company and
                      Parent on July 5, 2001.

(a)(2)                Not applicable.

(a)(3)                Not applicable.

(a)(4)                Not applicable.

(a)(5)(i)             Letter Agreement, dated as of June 20, 2001, by and among
                      the Company, Parent and Offeror.

(a)(5)(ii)            Letter Agreement, dated as of July 5, 2001, by and among
                      the Company, Parent and Offeror.

(b)                   Commitment Letter, dated as of April 24, 2001, by U.S.
                      Bank National Association and Parent.(1)

(b)(1)                Loan and Security Agreement, dated as of May 21, 2001, by
                      and among U.S. Bank National Association, Parent and other
                      signatories.(3)

(d)(1)                Agreement and Plan of Merger, dated as of April 2, 2001,
                      by and among the Company, Parent and Offeror (incorporated
                      by reference to Exhibit 99.2 to Parent's Schedule TO-C
                      filed April 3, 2001).

(d)(2)                Amendment No. 1 to Agreement and Plan of Merger, dated as
                      of May 15, 2001, by and among the Company, Parent and
                      Offeror.(2)

(d)(3)                Form of Tender and Voting Agreement, dated as of April 2,
                      2001, by and among Parent, Offeror and certain
                      shareholders of the Company (incorporated by reference to
                      Exhibit 99.3 to Parent's Schedule TO-C filed April 3,
                      2001).

(g)                   None.

(h)                   None.




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(1)  Previously filed on Schedule TO filed with the SEC on April 30, 2001.

(2)  Previously filed on Amendment No. 1 to Schedule TO filed with the SEC on
     May 16, 2001.

(3)  Previously filed on Amendment No. 2 to Schedule TO filed with the SEC on
     May 22, 2001.

(4)  Previously filed on Amendment No. 3 to Schedule TO filed with the SEC on
     May 25, 2001.

(5)  Previously filed on Amendment No. 4 to Schedule TO filed with the SEC on
     June 7, 2001.

(6)  Previously filed on Amendment No. 5 to Schedule TO filed with the SEC on
     June 19, 2001.


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