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                                                                     EXHIBIT 5.1

            [Letterhead of Skadden, Arps, Slate, Meagher & Flom LLP]


                                           June 24, 2004


Solo Cup Company and each of
     the entities listed on Schedules I and II hereto
1700 Old Deerfield Road
Highland Park, Illinois 60035

              Re:    Registration Statement on Form S-4 of Solo Cup Company and
                     Certain Subsidiaries of Solo Cup Company

Ladies and Gentlemen:

       We have acted as special United States counsel to Solo Cup Company, a
Delaware corporation (the "Company"), in connection with the public offering of
$325,000,000 aggregate principal amount of the Company's 8 1/2% Senior
Subordinated Notes due 2014 (the "Exchange Notes") and related guarantees by the
Note Guarantors (as defined below) (the "Guarantees"). The Exchange Notes and
the Guarantees are to be issued pursuant to an exchange offer (the "Exchange
Offer") in exchange for a like principal amount of the issued and outstanding 8
1/2% Senior Subordinated Notes due 2014 of the Company (the "Original Notes"),
together with guarantees thereof by the Note Guarantors, issued under an
Indenture dated as of February 27, 2004 (the "Indenture") among the Company, the
subsidiaries of the Company listed on the signature pages thereto (the "Initial
Guarantors") and U.S. Bank National Association, a nationally chartered banking
association, as trustee (the "Trustee"), as amended by the First Supplemental
Indenture, dated as of June 18, 2004 (the "Supplemental Indenture"), among (i)
the Company, (ii) the entities listed on Schedule I hereto (collectively, the
"U.S. Guarantors"), (iii) the entities listed on Schedule II hereto
(collectively, the "UK Guarantors" and, together with the U.S. Guarantors, the
"Note Guarantors") and (iv) the Trustee, as contemplated by the Registration
Rights Agreement, dated as of February 27, 2004 (the "Registration Rights
Agreement"), by and among the Company, the Initial Guarantors, Banc of America
Securities LLC, Citigroup Global Markets Inc., Harris Nesbitt Corp., ABN AMRO
Incorporated, Rabo-Securities USA, Inc. and Tokyo-Mitsubishi International plc.

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Solo Cup Company et al.
June 24, 2004
Page 2

       This opinion is being furnished in accordance with the requirements of
Item 601(b)(5) of Regulation S-K under the Securities Act of 1933, as amended
(the "Act").

       In connection with this opinion, we have examined and relied upon
originals or copies, certified or otherwise identified to our satisfaction, of
(i) the Registration Statement on Form S-4 with respect to the Exchange Notes
and the Guarantees to be filed with the Securities and Exchange Commission (the
"Commission") on the date hereof under the Act (the "Registration Statement");
(ii) an executed copy of the Registration Rights Agreement; (iii) an executed
copy of the Indenture; (iv) an executed copy of the Supplemental Indenture; (iv)
the certificate of incorporation, articles of incorporation or certificate of
organization, as applicable, of the Company and each of the U.S. Guarantors; (v)
the by-laws or company agreement, as applicable, of the Company and each of the
U.S. Guarantors; (vi) certain resolutions adopted by the board of directors,
sole manager, or sole member, as applicable, of the Company and each of the U.S.
Guarantors relating to the Indenture and the Supplemental Indenture, the
issuance of the Original Notes and guarantees thereof, the Exchange Offer, the
issuance of the Exchange Notes and the Guarantees and related matters; (vii) the
Statement of Eligibility Under the Trust Indenture Act of 1939 on Form T-1 of
the Trustee filed as Exhibit 25 to the Registration Statement; and (viii) forms
of the Exchange Notes and the Guarantees. We have also examined originals or
copies, certified or otherwise identified to our satisfaction, of such records
of the Company and the U.S. Guarantors and such agreements, certificates of
public officials, certificates of officers or other representatives of the
Company, the U.S. Guarantors and others, and such other documents as we have
deemed necessary or appropriate as a basis for the opinions set forth herein.

       In our examination, we have assumed the legal capacity of all natural
persons, the genuineness of all signatures, the authenticity of all documents
submitted to us as originals, the conformity to original documents of all
documents submitted to us as facsimile, electronic, certified or photostatic
copies and the authenticity of the originals of such copies. In making our
examination of documents executed or to be executed, we have assumed that the
parties thereto, other than the Company and the U.S. Guarantors, had or will
have the power, corporate or other, to enter into and perform all obligations
thereunder and have also assumed (i) the due authorization by all requisite
action, corporate or other, by the parties thereto, other than the Company and
the U.S. Guarantors, (ii) the execution

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Solo Cup Company et al.
June 24, 2004
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and delivery by such parties of such documents, other than the Company and the
U.S. Guarantors and (iii) except to the extent we opine on such matters below
with respect to the Exchange Notes and the Guarantees, the validity and binding
effect thereof on such parties. In rendering the opinions expressed below, we
have also assumed, without independent investigation or verification of any
kind, that the choice of New York law to govern such documents, which are stated
therein to be governed thereby, is legal and valid under the laws of other
applicable jurisdictions and that, insofar as any obligation under any such
document is to be performed in any jurisdiction outside the United States of
America, its performance will not be illegal or ineffective by virtue of the law
of that jurisdiction. In addition, we do not express any opinion as to the
effect on the opinions expressed herein of (i) the compliance or noncompliance
of any party to such documents (other than with respect to the Company and the
Note Guarantors to the extent necessary to render the opinions set forth herein)
with any state, federal or other laws or regulations applicable to it or them or
(ii) the legal or regulatory status or the nature of the business of any party
(other than with respect to the Company and the Note Guarantors to the extent
necessary to render the opinions set forth herein). As to any facts material to
the opinions expressed herein that we did not independently establish or verify,
we have relied upon statements and representations of officers and other
representatives of the Company, the Note Guarantors and others and of public
officials.

       Our opinions set forth herein are limited to the General Corporation Law
of the State of Delaware, the Delaware Limited Liability Company Act, the
Business Corporation Act of 1983 of the State of Illinois, the Texas Limited
Liability Company Act and the laws of the State of New York that, in our
experience, are normally applicable to transactions of the type contemplated by
the Exchange Offer and, to the extent that judicial or regulatory orders or
decrees or consents, approvals, licenses, authorizations, validations, filings,
recordings or registrations with governmental authorities are relevant, to those
required under such laws (all of the foregoing being referred to as "Opined on
Law"). We do not express any opinion with respect to the laws of any
jurisdiction other than the Opined on Law or as to the effect of any such
non-opined on law on the opinions herein stated.

       Based upon and subject to the foregoing and the limitations,
qualifications, exceptions and assumptions set forth herein, we are of the
opinion that, when the Exchange Notes and the Guarantees (in the forms examined
by us) have been duly

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Solo Cup Company et al.
June 24, 2004
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executed and authenticated in accordance with the terms of the Indenture and
Supplemental Indenture and have been delivered upon consummation of the Exchange
Offer against receipt of the Original Notes and the guarantees of the Original
Notes surrendered in exchange therefor in accordance with the terms of the
Exchange Offer, (i) the Exchange Notes will constitute valid and binding
obligations of the Company, enforceable against the Company in accordance with
their terms, and (ii) the Guarantee of each Note Guarantor will constitute the
valid and binding obligation of such Note Guarantor, enforceable against such
Note Guarantor in accordance with its terms, except (A) in each case, to the
extent that enforcement thereof may be limited by (1) bankruptcy, insolvency,
reorganization, moratorium or other similar laws now or hereafter in effect
relating to creditors' rights generally and (2) general principles of equity
(regardless of whether enforceability is considered in a proceeding at law or in
equity), (B) in each case, we do not express any opinion as to the applicability
or effect of any fraudulent transfer, preference or similar law on the
Indenture, the Supplemental Indenture, the Exchange Notes or the Guarantees or
any transactions contemplated thereby and (C) the waiver included in Section
4.06 of the Indenture may be unenforceable.

       In rendering the opinions set forth above, we have assumed that (1) the
execution and delivery by the Company of the Exchange Notes, by each U.S.
Guarantor of its Guarantee and by the Company and the U.S. Guarantors of the
Indenture and the Supplemental Indenture, and the performance by the Company and
the U.S. Guarantors of their respective obligations thereunder, do not and will
not violate, conflict with or constitute a default under any agreement or
instrument to which the Company, the U.S. Guarantors or their respective
properties are subject, except for those agreements and instruments which have
been identified to us by the Company as being material to the Company and its
subsidiaries and which are listed under Item 21(a) in Part II of the
Registration Statement as exhibits thereto (the "Listed Agreements and
Instruments"), (2) the execution and delivery by each UK Guarantor of its
Guarantee and the Supplemental Indenture, and the performance by UK Guarantors
of their respective obligations thereunder and under the Indenture, do not and
will not violate, conflict with or constitute a default under their respective
certificates of incorporation or memoranda and articles of association or under
any of the other Listed Agreements and Instruments and (3) each UK Guarantor is
in good standing under the laws of its jurisdiction of organization and (4)
insofar as any obligation under the Indenture, the Supplemental Indenture, the
Exchange Notes or the Guarantees is to be performed in, or by a party organized
under the laws of, any

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Solo Cup Company et al.
June 24, 2004
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jurisdiction outside the United States of America, its performance will not be
illegal or ineffective in any such jurisdiction by virtue of the law of that
jurisdiction. We note that certain of the Listed Agreements and Instruments are
governed by laws other than the Opined on Law. Our opinions expressed herein are
based solely upon our understanding of the plain language of such agreements or
instruments and we do not express any opinion with respect to the validity,
binding nature or enforceability of any such agreement or instrument, and we do
not assume any responsibility with respect to the effect on the opinions or
statements set forth herein of any interpretation thereof inconsistent with such
understanding.

       We hereby consent to the filing of this opinion with the Commission as an
exhibit to the Registration Statement. We also consent to the reference to our
firm under the caption "Legal Matters" in the Registration Statement. In giving
this consent, we do not thereby admit that we are included in the category of
persons whose consent is required under Section 7 of the Act or the rules and
regulations of the Commission.


                                    Very truly yours,

                                    /s/ Skadden, Arps, Slate, Meagher & Flom LLP


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                                   Schedule I

Solo Cup Company, an Illinois corporation
Solo Management Company, an Illinois corporation
P.R. SOLO CUP, INC., an Illinois corporation
SOLO TEXAS, LLC, a Texas limited liability company
SF Holdings Group, Inc., a Delaware corporation
Sweetheart Cup Company Inc., a Delaware corporation
Lily-Canada Holding Corporation, a Delaware corporation
Cupcorp, Inc., a Delaware corporation
EMERALD LADY INC., a Delaware corporation
Newcup, LLC, a Delaware limited liability company


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                                   Schedule II

Solo Cup (UK) Limited, a company organized under the laws of England and Wales
Insulpak Holdings Limited, a company organized under the laws of England and
Wales Solo Cup Europe Limited, a company organized under the laws of England and
Wales