<Page>

                                                                     EXHIBIT 4.5

                                  FORM OF NOTE

         [The following legend (the "Private Placement Legend") to be included
on all Notes (other than Exchange Notes) until such time as such legend has been
removed in accordance with the provisions of the Indenture--] THIS NOTE (AS
DEFINED IN THE INDENTURE REFERRED TO BELOW) HAS NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE
SECURITIES LAWS, AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD WITHIN THE UNITED
STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT OF, U.S. PERSONS EXCEPT AS SET FORTH
IN THE FOLLOWING SENTENCE. BY ITS ACQUISITION HEREOF, THE HOLDER (AS DEFINED IN
THE INDENTURE REFERRED TO BELOW) OF THIS NOTE (1) REPRESENTS THAT (A) IT IS A
"QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE SECURITIES
ACT) OR (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS DEFINED IN RULE
501(A)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT) (AN "INSTITUTIONAL
ACCREDITED INVESTOR") OR (C) IT IS NOT A U.S. PERSON AND IS ACQUIRING THIS NOTE
IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES
ACT; (2) AGREES THAT IT WILL NOT, PRIOR TO THE EXPIRATION OF THE HOLDING PERIOD
APPLICABLE TO SALES OF THE NOTE EVIDENCED HEREBY UNDER RULE 144(K) UNDER THE
SECURITIES ACT (OR ANY SUCCESSOR PROVISION), RESELL OR OTHERWISE TRANSFER THIS
NOTE EXCEPT (A) TO THE COMPANY (AS DEFINED BELOW) OR ONE OF ITS SUBSIDIARIES,
(B) TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE WITH RULE 144A UNDER THE
SECURITIES ACT, (C) TO AN INSTITUTIONAL ACCREDITED INVESTOR PURCHASING FOR ITS
OWN ACCOUNT OR FOR THE ACCOUNT OF ONE OR MORE OTHER INSTITUTIONAL ACCREDITED
INVESTORS OVER WHICH IT EXERCISES SOLE INVESTMENT DISCRETION AND THAT, PRIOR TO
SUCH TRANSFER, FURNISHES TO THE TRUSTEE (AS DEFINED BELOW) A SIGNED LETTER
CONTAINING CERTAIN REPRESENTATIONS AND AGREEMENTS RELATING TO THE RESTRICTIONS
ON TRANSFER OF THIS NOTE (THE FORM OF WHICH LETTER CAN BE OBTAINED FROM THE
TRUSTEE) AND, IF REQUESTED BY THE COMPANY, AN OPINION OF COUNSEL REASONABLY
ACCEPTABLE TO THE COMPANY TO THE EFFECT THAT THE TRANSFER IS BEING MADE PURSUANT
TO AN EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION
REQUIREMENTS OF THE SECURITIES ACT, PROVIDED THAT SUCH INSTITUTIONAL ACCREDITED
INVESTOR AND EACH SUCH INVESTOR ACCOUNT PURCHASES AT LEAST $250,000 AGGREGATE
PRINCIPAL AMOUNT OF THESE NOTES, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION
PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE), (E) PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT (AND WHICH CONTINUES
TO BE EFFECTIVE AT THE TIME OF THAT TRANSFER) OR (F) OUTSIDE THE UNITED STATES
IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE SECURITIES ACT,
PROVIDED THAT THE FOREGOING AGREEMENT OF THE HOLDER IS SUBJECT TO ANY
REQUIREMENT OF LAW THAT THE DISPOSITION OF THE PROPERTY OF THE HOLDER OR ANY
INVESTOR ACCOUNTS FOR WHICH THE HOLDER IS ACTING SHALL AT ALL TIMES BE AND
REMAIN WITHIN ITS OR THEIR CONTROL; AND (3) AGREES THAT IT WILL DELIVER TO EACH
PERSON TO WHOM THIS NOTE IS TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT OF
THIS LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS NOTE PRIOR TO EXPIRATION OF
THE HOLDING PERIOD APPLICABLE TO SALES OF THE NOTE EVIDENCED HEREBY UNDER RULE
144(K) UNDER THE SECURITIES ACT (OR ANY SUCCESSOR PROVISION), THE HOLDER MUST
CHECK THE APPROPRIATE BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE MANNER
OF SUCH TRANSFER AND SUBMIT THIS NOTE TO THE TRUSTEE.

         [The following legend (the "Private Placement Legend") to be included
on all Notes (other than Exchange Notes) until such time as such legend has been
removed in accordance with the provisions of the Indenture--] IF THE PROPOSED
TRANSFEREE IS AN INSTITUTIONAL ACCREDITED INVESTOR OR IF THE

                                      1
<Page>

PROPOSED TRANSFER IS BEING MADE OUTSIDE THE UNITED STATES IN COMPLIANCE WITH
RULE 904 UNDER THE SECURITIES ACT OR PURSUANT TO RULE 144 UNDER THE SECURITIES
ACT (IF AVAILABLE), THE HOLDER MUST, PRIOR TO SUCH TRANSFER, FURNISH TO THE
TRUSTEE, SUCH CERTIFICATIONS, LEGAL OPINIONS OR OTHER INFORMATION AS THE COMPANY
MAY REASONABLY REQUIRE TO CONFIRM THAT SUCH TRANSFER IS BEING MADE PURSUANT TO
AN EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION
REQUIREMENTS OF THE SECURITIES ACT. THE FOREGOING LEGENDS WILL BE REMOVED UPON
THE EARLIER OF THE TRANSFER OF THE NOTE EVIDENCED HEREBY PURSUANT TO CLAUSE 2(E)
ABOVE OR UPON ANY TRANSFER OF THIS NOTE UNDER RULE 144(K) UNDER THE SECURITIES
ACT (OR ANY SUCCESSOR PROVISION).

         [The following legend (the "Private Placement Legend") to be included
on all Notes (other than Exchange Notes) until such time as such legend has been
removed in accordance with the provisions of the Indenture--] AS USED IN THE
LEGENDS SET FORTH ABOVE, THE TERMS "OFFSHORE TRANSACTION," "UNITED STATES" AND
"U.S. PERSON" HAVE THE MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE
SECURITIES ACT.

         [Include the following legend (the "DTC Legend") only in Global
Notes--] THIS NOTE (AS DEFINED IN THE INDENTURE REFERRED TO BELOW) IS A GLOBAL
SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS
REGISTERED IN THE NAME OF A DEPOSITORY OR A NOMINEE THEREOF. THIS NOTE IS
EXCHANGEABLE FOR NOTES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE
DEPOSITORY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE
INDENTURE AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR
INDIVIDUAL NOTES REPRESENTED HEREBY, THIS GLOBAL NOTE MAY NOT BE TRANSFERRED
EXCEPT AS A WHOLE BY THE DEPOSITORY TO A NOMINEE OF THE DEPOSITORY OR BY A
NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR ANOTHER NOMINEE OF THE DEPOSITORY
OR BY THE DEPOSITORY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITORY OR A NOMINEE
OF SUCH SUCCESSOR DEPOSITORY.

         [Include the following legend (the "DTC Legend") only in Global Notes
registered in the name of The Depository Trust Company--] UNLESS THIS NOTE IS
PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW
YORK CORPORATION ("DTC"), TO THE COMPANY (AS DEFINED BELOW) OR ITS AGENT FOR
REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY NOTE ISSUED IS REGISTERED
IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER
ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER,
PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS
WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.

                                      2
<Page>

No.:   [-]

CUSIP No.:  [____________] [144A]                       Principal Amount:  $[-]
            [____________] [A/I]           [FOR INCLUSION IN GLOBAL SECURITIES--
            [____________] [EXCHANGE NOTES](or such other principal amount as is
            [____________] [REG.S]              set forth on Schedule A hereto)]

ISIN No.:   [____________] [144A]
            [____________] [A/I]
            [____________] [EXCHANGE NOTES]
            [____________] [REG.S]

                        PACKAGING CORPORATION OF AMERICA

                [4 3/8%] [5 3/4%] SENIOR NOTES DUE [2008] [2013]

         Packaging Corporation of America, a corporation duly organized and
existing under the General Corporation Law of the State of Delaware (hereinafter
called the "Company," which term includes any successor under the Indenture
referred to below), for value received, hereby promises to pay to Cede & Co., or
registered assigns, the principal sum of [-] DOLLARS ($[-]) (or such other
principal amount as is set forth on Schedule A hereto) on August 1, [2008]
[2013], and to pay interest thereon from and including July 21, 2003, or from
and including the most recent date to which interest has been paid or duly
provided for, to, but not including, the applicable Interest Payment Date (as
defined below) or Maturity, as the case may be. The Company will pay interest
semiannually in arrears on February 1 and August 1 of each year (each, an
"Interest Payment Date"), commencing February 1, 2004, and at Maturity, at the
rate of [4 3/8%] [5 3/4%] per annum, until the principal hereof is paid or duly
made available for payment. Interest on this Note shall be calculated on the
basis of a 360-day year consisting of twelve 30-day months. The interest so
payable and punctually paid or duly provided for on any Interest Payment Date
will, as provided in such Indenture, be paid to the Person in whose name this
Note (or one or more Predecessor Securities) is registered at the close of
business on the Regular Record Date for such interest, which shall be the
January 15 or July 15 (whether or not a Business Day), as the case may be, next
preceding such Interest Payment Date. Any such interest which is payable, but is
not punctually paid or duly provided for, on any Interest Payment Date shall
forthwith cease to be payable to the Person who was the Holder hereof on the
relevant Regular Record Date by virtue of having been such Holder, and may be
paid to the Person in whose name this Note (or one or more Predecessor
Securities) is registered at the close of business on a Special Record Date for
the payment of such Defaulted Interest to be fixed by the Trustee, notice
whereof shall be given to the Holder of this Note not less than 10 days prior to
such Special Record Date, or may be paid at any time in any other lawful manner
not inconsistent with the requirements of any securities exchange on which the
Notes may be listed, and upon such notice as may be required by such exchange,
all as more fully provided in such Indenture.

         Payment of the principal of and premium, if any, and the interest on
this Note will be made at the office or agency of the Company maintained for
that purpose in the Borough of Manhattan, The City of New York, in such coin or
currency of the United States of America as at the time of payment is legal
tender for payment of public and private debts; provided, however, that, at the
option of the Company, interest may be paid by check mailed to the address of
the Person entitled thereto as such address shall appear in the Security
Register or by transfer to an account maintained by the payee with a bank
located in the United States.

         This Note is one of a duly authorized issue of Securities of the
Company (herein called the "Notes") issued and to be issued in one or more
series under an Indenture dated as of July 21, 2003 (the "Original Indenture"),
as amended and supplemented by the First Supplemental Indenture dated as of July
21, 2003 (the "First Supplemental Indenture" and the Original Indenture, as
amended and supplemented by the First Supplemental Indenture and any other
indentures supplemental thereto, the "Indenture"), each between the Company and
U.S. Bank National Association, as trustee (herein called the "Trustee," which
term includes any successor trustee under the Indenture), to which Indenture and
all indentures supplemental thereto reference is hereby made for a statement of
the respective rights, limitations of rights, duties and immunities thereunder
of the Company, the Trustee and the Holders of the Notes, and the terms upon
which the Notes are, and are to be, authenticated and delivered. This Note

                                      3
<Page>

is one of the series designated on the face hereof, initially limited (subject
to exceptions provided in the Indenture) in aggregate principal amount to
[$150,000,000] [$400,000,000], subject to the right of the Company, without the
consent of the Holders of the Notes, to "reopen" such series and to issue
additional Notes of such series on the terms and subject to the conditions
provided in or pursuant to the Indenture.

         The Notes may be redeemed by the Company, in whole or from time to time
in part, at the option of the Company on any date at a Redemption Price equal to
the greater of (i) 100% of the principal amount of the Notes to be redeemed and
(ii) the sum of the present values of the remaining scheduled payments of
principal and interest on the Notes to be redeemed (exclusive of interest
accrued to the applicable Redemption Date) discounted to such Redemption Date on
a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months)
at the Treasury Rate plus [25] [30] basis points, plus, in the case of both
clause (i) and clause (ii) above, accrued and unpaid interest on the principal
amount of the Notes being redeemed up to, but not including, such Redemption
Date; provided, however, that installments of interest whose Stated Maturity is
on or prior to the Redemption Date will be payable to the Holders of the Notes
(or one or more Predecessor Notes) registered as such at the close of business
on the relevant Regular Record Dates according to their terms and the provisions
of the Indenture. Any such redemption shall be effected in accordance with the
terms and conditions set forth in the Indenture.

         As used in this Note, the following terms have the meaning set forth
below:

         "Treasury Rate" means, with respect to any Redemption Date for the
Notes, (i) the yield, under the heading that represents the average for the
immediately preceding week, appearing in the most recently published statistical
release designated "H.15 (519)" or any successor publication which is published
weekly by the Board of Governors of the Federal Reserve System and which
establishes yields on actively traded United States Treasury securities adjusted
to constant maturity under the caption "Treasury Constant Maturities," for the
maturity corresponding to the Comparable Treasury Issue (if no maturity is
within three months before or after the Final Maturity Date for the Notes,
yields for the two published maturities most closely corresponding to the
Comparable Treasury Issue shall be determined and the Treasury Rate shall be
interpolated or extrapolated from such yields on a straight line basis, rounding
to the nearest month) or (ii) if such release (or any successor release) is not
published during the week preceding the calculation date or does not contain
such yields, the rate per annum equal to the semi-annual equivalent yield to
maturity of the Comparable Treasury Issue, calculated using a price for the
Comparable Treasury Issue (expressed as a percentage of its principal amount)
equal to the Comparable Treasury Price for such Redemption Date. The Treasury
Rate shall be calculated on the third Business Day preceding the applicable
Redemption Date. As used in the immediately preceding sentence and in the
definition of "Reference Treasury Dealer Quotations" below, the term "Business
Day" means each Monday, Tuesday, Wednesday, Thursday and Friday which is not a
day on which banking institutions in The City of New York are authorized or
obligated by law, regulation or executive order to close.

         "Comparable Treasury Issue" means, with respect to any Redemption Date
for the Notes, the United States Treasury security selected by the Independent
Investment Banker as having a maturity comparable to the remaining term of the
Notes to be redeemed that would be utilized, at the time of selection and in
accordance with customary financial practice, in pricing new issues of corporate
debt securities of comparable maturity to the remaining term of the Notes.

         "Comparable Treasury Price" means, with respect to any Redemption Date
for the Notes, (i) the average of five Reference Treasury Dealer Quotations for
such Redemption Date, after excluding the highest and lowest such Reference
Treasury Dealer Quotations, (ii) if the Trustee obtains fewer than five but more
than one such Reference Treasury Dealer Quotations for such Redemption Date, the
average of all such quotations or (iii) if the Trustee obtains only one such
Reference Treasury Dealer Quotation for such Redemption Date, that Reference
Treasury Dealer Quotation.

         "Final Maturity Date" means August 1, [2008] [2013].

         "Independent Investment Banker" means, with respect to any Redemption
Date for the Notes, Morgan Stanley & Co. Incorporated and its successors or
Citigroup Global Markets Inc. and its successors, whichever is selected by the
Trustee after consultation with the Company, or, if both such firms or the
respective successors, if any, to such firms, as the case may be, are unwilling
or unable to select the Comparable Treasury Issue, an

                                      4
<Page>

independent investment banking institution of national standing in the United
States of America appointed by the Trustee after consultation with the Company.

         "Reference Treasury Dealers" means, with respect to any Redemption Date
for the Notes, Morgan Stanley & Co. Incorporated and Citigroup Global Markets
Inc. and their respective successors (provided, however, that if either such
firm or any such successor, as the case may be, ceases to be a primary U.S.
Government securities dealer in New York City (a "Primary Treasury Dealer"), the
Trustee, after consultation with the Company, shall substitute therefor another
Primary Treasury Dealer) and three other Primary Treasury Dealers selected by
the Trustee after consultation with the Company.

         "Reference Treasury Dealer Quotations" means, with respect to each
Reference Treasury Dealer and any Redemption Date for the Notes, the average, as
determined by the Trustee, of the bid and asked prices for the Comparable
Treasury Issue (expressed in each case as a percentage of its principal amount)
quoted in writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m.,
New York City time, on the third Business Day preceding such Redemption Date.

         Notice of any redemption will be mailed at least 30 days but not more
than 60 days before the applicable Redemption Date to each Holder of the Notes
to be redeemed at such Holder's registered address.

         Unless the Company defaults in payment of the Redemption Price, on and
after the applicable Redemption Date interest will cease to accrue on the Notes
or portions thereof called for redemption on such Redemption Date.

         If an Event of Default with respect to the Notes shall occur and be
continuing, the principal of and accrued and unpaid interest on the Notes may be
declared due and payable in the manner and with the effect provided in the
Indenture.

         In addition to rights provided to the Holders of the Notes under the
Indenture, Holders of Notes shall have all the rights set forth in the
Registration Rights Agreement, dated as of July 21, 2003, between the Company
and Morgan Stanley & Co. Incorporated and Citigroup Global Markets Inc., as
representatives of certain initial purchasers (as the same may be amended or
supplemented from time to time in accordance with its terms, the "Registration
Rights Agreement"). Pursuant to the Registration Rights Agreement, the Holders
of the Notes will, subject to certain exceptions and on the terms and subject to
the conditions specified in the Registration Rights Agreement, have the right to
exchange their Notes for a like principal amount of Exchange Notes of the same
series issued under the Indenture and evidencing the same continuing
indebtedness of the Company as the Notes, which Exchange Notes will have been
registered under the Securities Act. The Holders of the Notes shall be entitled
to receive Additional Interest (as defined in the Registration Rights Agreement)
on the Notes in the event such Exchange Offer is not consummated or upon certain
other conditions, all on the terms and subject to the conditions set forth in
the Registration Rights Agreement.

         The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of Securities of each series issued under
the Indenture at any time by the Company and the Trustee with the consent of the
Holders of not less than a majority in aggregate principal amount of the
Securities at the time Outstanding of each series affected thereby. The
Indenture also contains provisions permitting the Holders of specified
percentages in aggregate principal amount of the Securities of any series at the
time Outstanding, on behalf of the Holders of all Securities of such series, to
waive compliance by the Company with certain provisions of the Indenture and
certain past defaults under the Indenture and their consequences. Any such
consent or waiver by the Holder of this Note shall be conclusive and binding
upon such Holder and upon all future Holders of this Note and of any Notes
issued upon the registration of transfer hereof or in exchange herefor or in
lieu hereof, whether or not notation of such consent or waiver is made upon this
Note. The Indenture also permits the Company and the Trustee, without notice to
or consent of the Holders of the Notes, to enter into one or more indentures
supplemental thereto for the purposes specified in the Indenture.

         No reference herein to the Indenture and no provision of this Note or
of the Indenture shall alter or impair the obligation of the Company, which is
absolute and unconditional, to pay the principal of and premium, if any, and
interest on this Note at the time, place and rate, and in the coin or currency,
herein and in the Indenture prescribed.

                                      5
<Page>

         As provided in the Indenture and subject to certain limitations set
forth therein, the transfer of this Note may be registered on the Security
Register upon surrender of this Note for registration of transfer at the Office
or Agency of the Company maintained for the purpose in any place where the
principal of and interest on this Note are payable, duly endorsed, or
accompanied by a written instrument of transfer in form satisfactory to the
Company and the Security Registrar duly executed by the Holder hereof or by his
attorney duly authorized in writing, and thereupon one or more new Notes, of
authorized denominations and for the same aggregate principal amount, will be
issued to the designated transferee or transferees.

         The Notes are issuable only in registered form without coupons in
denominations of $1,000 and integral multiples of $1,000 in excess thereof. As
provided in the Indenture and subject to certain limitations set forth therein,
the Notes are exchangeable for a like aggregate principal amount of Notes of
authorized denominations as requested by the Holders surrendering the same.

         No service charge shall be made for any such registration of transfer
or exchange, but the Company may require payment of a sum sufficient to cover
any tax or other governmental charge payable in connection therewith, other than
in certain cases provided in the Indenture.

         Prior to due presentment of this Note for registration of transfer, the
Company, the Trustee and any agent of the Company or the Trustee may treat the
Person in whose name this Note is registered as the owner hereof for all
purposes, whether or not this Note shall be overdue, and neither the Company,
the Trustee nor any such agent shall be affected by notice to the contrary.

         The Indenture contains provisions whereby (i) the Company may be
discharged from its obligations with respect to the Notes (subject to certain
exceptions) or (ii) the Company may be released from its obligations under
specified covenants and agreements in the Indenture, in each case if the Company
irrevocably deposits with the Trustee money or Government Obligations sufficient
to pay and discharge the entire indebtedness on all Notes, and satisfies certain
other conditions, all as more fully provided in the Indenture. In addition, the
Indenture shall cease to be of further effect (subject to certain exceptions)
with respect to the Notes when (1) either (A) all Notes previously authenticated
and delivered have been delivered (subject to certain exceptions) to the Trustee
for cancellation, or (B) all Notes (i) have become due and payable, (ii) will
become due and payable at their Stated Maturity within one year or (iii) are to
be called for redemption within one year and, in the case of (i), (ii) or (iii)
of this sentence, the Company has irrevocably deposited with the Trustee money
in an amount sufficient to pay and discharge the entire indebtedness on all such
Notes not theretofore delivered to the Trustee for cancellation, and (2) the
Company satisfies certain other conditions, all as more fully provided in the
Indenture.

         This Note shall be governed by and construed in accordance with the
laws of the State of New York.

         All terms used in this Note which are defined in the Indenture and not
defined herein shall have the meanings assigned to them in the Indenture.

         Unless the certificate of authentication hereon has been executed by or
on behalf of the Trustee under the Indenture by the manual signature of one of
its authorized signatories, this Note shall not be entitled to any benefits
under the Indenture or be valid or obligatory for any purpose.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                      6
<Page>

IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed.


                                                Packaging Corporation of America


                                                By:
                                                     ---------------------------


Dated:

 TRUSTEE'S CERTIFICATE OF
 AUTHENTICATION
 This is one of the Notes of the series designated therein
 referred to in the within-mentioned Indenture.

 U.S. Bank National Association,
 as Trustee


 By:
      -------------------------------
            Authorized Signatory

                                      7
<Page>

                                  ABBREVIATIONS

         The following abbreviations, when used in the inscription on the face
of this instrument, shall be construed as though they were written out in full
according to applicable laws or regulations:

<Table>
                                                                
TEN COM--as tenants in common                 UNIF GIFT MIN ACT--                Custodian
TEN ENT--as tenants by the entireties                                 -----------------------------
JT TEN--as joint tenants with right of                                  (Cust)              (Minor)
survivorship and not as tenants in common                             Under Uniform Gifts to Minors
                                                                      Act
                                                                        ------------------------
                                                                                 (State)
</Table>

     Additional abbreviations may also be used though not in the above list.

                                   ----------

FOR VALUE RECEIVED, the undersigned registered holder hereby sell(s), assign(s)
and transfer(s) unto

PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE



________________________________________________________________________________
             PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS OF ASSIGNEE

________________________________________________________________________________
the within security and all rights thereunder, hereby irrevocably constituting
and appointing

_______________________________________________________________________ Attorney
to transfer said security on the books of the Company with full power of
substitution in the premises.


Dated:                                   Signed:
      ------------------------------            --------------------------------


                  Notice: The signature to this assignment must correspond with
         the name as it appears upon the face of the within security in every
         particular, without alteration or enlargement or any change whatever.

                                      8
<Page>

                              TRANSFER CERTIFICATE

         Capitalized terms used but not defined in this Certificate shall have
the meanings given to such terms in the Indenture referred to above.

         The undersigned (the "Transferor") has requested a transfer of this
[4 3/8%] [5 3/4%] Senior Note due [2008] [2013] (the "Notes") or a portion
hereof (the "Specified Notes").

         In connection with such request, the Transferor does hereby certify
that such transfer is being made pursuant to an effective registration statement
under the Securities Act of 1933, as amended (the "Securities Act") (as
indicated by the applicable box checked below), or the transfer does not require
registration under the Securities Act because (as indicated by the applicable
box checked below):

         / /      (a)      The  Specified  Notes  are  being  transferred
                           pursuant  to an  effective  registration statement
                           under the Securities Act.

         / /      (b)      The  Specified  Notes are being  acquired  for the
                           Transferor's  own  account,  without transfer.

         / /      (c)      The  Specified  Notes  are being  transferred  to the
                           Company  or a  subsidiary  of the Company.

         / /      (d)      The Specified Notes are being transferred in
                           compliance with Rule 144A ("Rule 144A") under the
                           Securities Act to a person the Transferor reasonably
                           believes is a "qualified institutional buyer" (as
                           defined in Rule 144A) that is purchasing the
                           Specified Notes for its own account or for the
                           account of another "qualified institutional buyer,"
                           in each case to whom notice has been given that the
                           transfer is being made in reliance on Rule 144A.

         / /      (e)      The Specified Notes are being transferred to an
                           institutional "accredited investor" (as defined in
                           Rule 501(a)(1), (2), (3) or (7) under the Securities
                           Act) (an "Institutional Accredited Investor")
                           purchasing for its own account or for the account of
                           one or more other Institutional Accredited Investors
                           over which it exercises sole investment discretion,
                           in each case in a minimum principal amount of
                           U.S.$250,000, and that, prior to such transfer,
                           furnishes to the Trustee a signed letter containing
                           certain representations and agreements relating to
                           the restrictions on transfer of the Specified Notes
                           (the form of which letter can be obtained from the
                           Trustee) and, if the Company requests, an opinion of
                           counsel reasonably acceptable to the Company to the
                           effect that the transfer is being made pursuant to an
                           exemption from, or in a transaction not subject to,
                           the registration requirements of the Securities Act.

         / /      (f)      The Specified Notes are being transferred
                           pursuant to and in compliance with an exemption from
                           the registration requirements of the Securities Act
                           provided by Rule 144 under the Securities Act (if
                           available).

         / /      (g)      The Specified Notes are being transferred outside
                           the "United States" (as defined in Regulation S
                           ("Regulation S") under the Securities Act) in an
                           "offshore transaction" (as defined in Regulation S)
                           in compliance with Rule 904 under the Securities Act.

                                      9
<Page>

This Certificate and the statements contained herein are made for the benefit of
the Trustee and the Company.

Dated:
        ----------------------------       -------------------------------------
                                           (Insert Name of Transferor)


                                           By:
                                               ---------------------------------
                                           Notice: The signature to this
                                           Certificate must correspond with the
                                           name as it appears upon the face of
                                           the within security in every
                                           particular, without alteration or
                                           enlargement or any change whatever

To be completed by transferee
if (d) above is checked:

         The undersigned transferee represents and warrants that (i) it is a
"qualified institutional buyer" as defined in Rule 144A under the Securities Act
of 1933 (the "Securities Act") and is aware that the Specified Notes (as defined
above) are being transferred in reliance on 144A under the Securities Act, (ii)
the undersigned is acquiring the Specified Notes for its own account or for the
account of one or more other "qualified institutional buyers" over which it
exercises sole investment discretion (in which latter case the undersigned has
given notice to each such account that the Specified Notes are being transferred
in reliance on Rule 144A) and (iii) this instrument has been executed on behalf
of the undersigned by one of its executive officers. The undersigned transferee
acknowledges and agrees that the Specified Notes have not been registered under
the Securities Act and may not be transferred except in accordance with the
resale and other transfer restrictions set forth on the face thereof.

Dated:
        ----------------------------       -----------------------------------
                                           (Insert Name of Transferee)


                                           By:
                                               -------------------------------
                                                       Executive Officer

                                      10
<Page>

                                   SCHEDULE A

         The initial principal amount of this Global Note is [-] DOLLARS ($[-]).
The following increases or decreases in the principal amount of this Global Note
have been made:

<Table>
<Caption>
                                                             Principal amount of
                 Amount of increase    Amount of decrease    this Global Note       Signature of
                 in principal amount   in principal amount   following such         authorized signatory
Date made        of this Global Note   of this Global Note   decrease or increase   of Trustee
- --------------   -------------------   -------------------   --------------------   ---------------------
                                                                        



</Table>

                                      11