<Page>

                                                                   EXHIBIT 3.9

                          CERTIFICATE OF INCORPORATION

                                       OF

                            PREFACE ACQUISITION CORP.

          THE UNDERSIGNED, being a natural person for the purpose of organizing
a corporation under the General Corporation Law of the State of Delaware, hereby
certifies that:

          FIRST: The name of the Corporation is Preface Acquisition Corp.

          SECOND: The address of the registered office of the Corporation in the
State of Delaware is 1209 Orange Street, City of Wilmington, County of New
Castle, State of Delaware. The name of the registered agent of the Corporation
in the state of Delaware at such address is The Corporation Trust Company.

          THIRD: The purpose of the Corporation is to engage in any lawful act
or activity for which corporations may be organized under the General
Corporation Law of the State of Delaware, as from time to time amended.

          FOURTH: The total number of shares of capital stock which the
Corporation shall have authority to issue is One Thousand (1,000), all of which
shares shall be Common Stock having a par value of $0.01.

          FIFTH: The name and mailing address of the incorporator is Stuart C.
Hirsch, c/o Weil, Gotshal & Manges LLP, 767 Fifth Avenue, New York, New York
10153.

          SIXTH: In furtherance and not in limitation of the powers conferred by
law, subject to any limitations contained elsewhere in these articles of
incorporation, by-laws of the Corporation may be adopted, amended or repealed by
a majority of the board of directors of the Corporation, but any by-laws adopted
by the board of directors may be amended or repealed by the stockholders
entitled to vote thereon. Election of directors need not be by written ballot.

          SEVENTH: The Corporation shall indemnify, to the full extent permitted
by Section 145 of the General

<Page>

Corporation Law of Delaware, as amended from time to time, all persons whom it
may indemnify pursuant thereto. No director shall be personally liable to the
Corporation or any stockholder for monetary damages for breach of fiduciary duty
as a director, except for any matter in respect of which such director shall be
liable under Section 174 of Title 8 of the General Corporation Law of Delaware
or any amendment thereto or successor provision thereto or shall be liable by
reason that, in addition to any and all other requirements for such liability,
such director (i) shall have breached his or her duty of loyalty to the
Corporation or its stockholders, (ii) shall not have acted in good faith or, in
failing to act, shall not have acted in good faith, (iii) shall have acted in a
manner involving intentional misconduct or a knowing violation of law or, in
failing to act, shall have acted in a manner involving intentional misconduct or
a knowing violation of law or (iv) shall have derived an improper personal
benefit. Neither the amendment nor repeal of this Article Seventh nor the
adoption of any provision of the Certificate of Incorporation inconsistent with
this Article Seventh, shall eliminate or reduce the effect of this Article
Seventh in respect of any matter occurring, or any cause of action, suit or
claim that, but for this Article Seventh, would accrue or arise, prior to such
amendment, repeal or adoption of an inconsistent provision.

          IN WITNESS WHEREOF, the undersigned has duly executed this Certificate
of Incorporation on this 8th day of May, 1998.


                                                      /s/ Stuart C. Hirsch
                                                      --------------------------
                                                      Stuart C. Hirsch
                                                      Sole Incorporator

                                        2