Exhibit 4.3



SECOND SUPPLEMENTAL INDENTURE



dated as of September 23, 2015



to the

INDENTURE



dated as of June 19, 2014

among



CASCADES INC.,

THE SUBSIDIARY GUARANTORS named therein, and

WELLS FARGO BANK, NATIONAL ASSOCIATION,



as Trustee











second SUPPLEMENTAL
INDENTURE



SECOND SUPPLEMENTAL INDENTURE (this “Second
Supplemental Indenture”), dated as of September 23, 2015, among Cascades Flexible Packaging Inc. (the “Guaranteeing
Subsidiary”), Cascades Inc., a corporation organized under the laws of the Province of Quebec, Canada (the “Company”),
and Wells Fargo Bank, National Association, as Trustee under the Indenture referred to below.



WITNESSETH:



WHEREAS, each of the Company, the Subsidiary
Guarantors and the Trustee have heretofore executed and delivered an indenture dated as of June 19, 2014 (as amended, supplemented,
waived or otherwise modified, the “Indenture”), providing for the issuance of its 5.50% Senior Notes due 2022
(the “Notes”);



WHEREAS, the Indenture provides that under certain
circumstances the Guaranteeing Subsidiary shall execute and deliver to the Trustee a supplemental indenture to which the Guaranteeing
Subsidiary shall unconditionally guarantee, on a joint and several basis with the other Subsidiary Guarantors, all of the Company’s
Obligations under the Notes and the Indenture on the terms and conditions set forth herein and under the Indenture (the “Guarantee”);
and



WHEREAS, pursuant to Section 9.01 of the Indenture,
the Company and the Trustee are authorized to execute and deliver this Second Supplemental Indenture to amend or supplement the
Indenture, without the consent of any Holder;



NOW, THEREFORE, in consideration of the foregoing
and for other good and valuable consideration, the receipt of which is hereby acknowledged, the Guaranteeing Subsidiary, the Company
and the Trustee mutually covenant and agree for the equal and ratable benefit of the Holders of the Notes as follows:



ARTICLE
I
DEFINITIONS



Section
1.1Defined Terms. As used in this Second Supplemental Indenture, terms defined in the Indenture or in the preamble
or recitals hereto are used herein as therein defined. The words “herein,” “hereof” and “hereby”
and other words of similar import used in this Second Supplemental Indenture refer to this Second Supplemental Indenture as a whole
and not to any particular section hereof.



ARTICLE
II
AGREEMENT TO BE BOUND; GUARANTEE



Section
2.1Agreement to be Bound. The Guaranteeing Subsidiary hereby becomes a party to the Indenture as a Subsidiary
Guarantor and as such will have all of the rights and be subject to all of the obligations and agreements of a Subsidiary Guarantor
under the Indenture.



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Section
2.2Subsidiary Guarantee. The Guaranteeing Subsidiary agrees to fully, unconditionally and irrevocably Guarantee
to each Holder of the Notes and the Trustee the Obligations pursuant to Article 10 of the Indenture on a senior basis and this
Second Supplemental Indenture shall constitute evidence of the Guaranteeing Subsidiary’s Subsidiary Guarantee.



ARTICLE
III
MISCELLANEOUS



Section
3.1Notices. All notices and other communications to the Guaranteeing Subsidiary shall be given as provided in
the Indenture to the Guaranteeing Subsidiary, with a copy to the Company as provided in the Indenture for notices to the Company.



Section
3.2Parties. Nothing expressed or mentioned herein is intended or shall be construed to give any Person, firm
or corporation, other than the Holders and the Trustee, any legal or equitable right, remedy or claim under or in respect of this
Second Supplemental Indenture or the Indenture or any provision herein or therein contained.



Section
3.3Governing Law. This Second Supplemental Indenture shall be governed by, and construed in accordance with,
the laws of the State of New York.



Section
3.4Severability. In case any provision in this Second Supplemental Indenture shall be invalid, illegal or unenforceable,
the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby and
such provision shall be ineffective only to the extent of such invalidity, illegality or unenforceability.



Section
3.5Benefits Acknowledged. The Guaranteeing Subsidiary’s Guarantee is subject to the terms and conditions
set forth in the Indenture. The Guaranteeing Subsidiary acknowledges that it will receive direct and indirect benefits from the
financing arrangements contemplated by the Indenture and that the guarantee and waivers made by it pursuant to this Guarantee are
knowingly made in contemplation of such benefits.



Section
3.6Ratification of Indenture; Second Supplemental Indenture Part of Indenture. Except as expressly amended hereby,
the Indenture is in all respects ratified and confirmed and all the terms, conditions and provisions thereof shall remain in full
force and effect. This Second Supplemental Indenture shall form a part of the Indenture for all purposes, and every Holder of Notes
heretofore or hereafter authenticated and delivered shall be bound hereby.



Section
3.7The Trustee. The Trustee makes no representation or warranty as to the validity or sufficiency of this Second
Supplemental Indenture or with respect to the recitals contained herein, all of which recitals are made solely by the other parties
hereto.



Section
3.8Counterparts. The parties hereto may sign any number of copies of this Second Supplemental Indenture. Each
signed copy shall be an original, but all of them together represent the same agreement. The exchange of copies of this Second
Supplemental Indenture and of signature pages by facsimile or PDF transmission shall constitute effective execution and



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delivery of this Second Supplemental Indenture
as to the parties hereto and may be used in lieu of the original Second Supplemental Indenture for all purposes. Signatures of
the parties hereto transmitted by facsimile or PDF shall be deemed to be their original signatures for all purposes.



Section
3.9Execution and Delivery. The Guaranteeing Subsidiary agrees that the Guarantee shall remain in full force and
effect notwithstanding any failure to endorse on each Note a notation of any such Guarantee.



Section
3.10Headings. The headings of the Articles and the Sections in this Second Supplemental Indenture are for convenience
of reference only and shall not be deemed to alter or affect the meaning or interpretation of any provisions hereof.



Section
3.11FATCA. This Second Supplemental Indenture has not resulted in a material modification of the issuance for
purposes of the Foreign Account Tax Compliance Act (FATCA) provisions of the Internal Revenue Code.



[The remainder of this page is intentionally
left blank.]



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IN WITNESS WHEREOF, the parties hereto have
caused this Second Supplemental Indenture to be duly executed as of the date first above written.



| | CASCADES INC.                    
| | ---------------------------------
| |                                  
| | By:                              
| |                                  
| |                                  
| |                                  
| |                                  
| | CASCADES FLEXIBLE PACKAGING INC.,
| | as the Guaranteeing Subsidiary   
| |                                  
| | By:                              
| |                                  
| |                                  



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| | WELLS FARGO BANK, NATIONAL ASSOCIATION,
| | ---------------------------------------
| | as Trustee                             
| |                                        
| | By:                                    
| |                                        
| |