Exhibit 5.3

November 26, 2013

To Each of the Persons Listed

on Schedule A Attached Hereto

Ladies and Gentlemen:

We have acted as special Delaware counsel for each of the Delaware corporations listed on Schedule B attached hereto (each, a “Corporation” and collectively, the “Corporations”) and each of the Delaware limited liability companies listed on Schedule C attached hereto (each, an “LLC” and collectively, the “LLCs”), in connection with the matters set forth herein. At your request, this opinion is being furnished to you.

For purposes of giving the opinions hereinafter set forth, our examination of documents has been limited to the examination of executed or conformed counterparts, or copies otherwise proved to our satisfaction, of the following:

(a) Each of the documents listed on Schedule D attached hereto (each, a “Certificate of Incorporation”), as filed in the office of the Secretary of State of the State of Delaware (the “Secretary of State”);

(b) The bylaws of each of the Corporations, as amended and/or restated through the date hereof (each, “Bylaws”);

(c) Resolutions adopted by the unanimous written consent of the board of directors of each of the Corporations, each dated September 30, 2013;

(d) Each of the documents listed on Schedule E attached hereto (each, an “LLC Certificate”), as filed in the office of the Secretary of State;

(e) Each of the documents listed on Schedule F attached hereto (each, an “LLC Agreement”);

(f) Resolutions adopted by the unanimous written consent of the sole member, the managers and/or directors, as applicable, of each of the LLCs, each dated September 30, 2013;

To Each of the Persons Listed

  on Schedule A Attached Hereto

November 26, 2013

Page 2

(g) The Senior Indenture (including the Subsidiary Guarantees of the Subsidiary Guarantors (each as defined therein) set forth therein), dated as of November 19, 2007 (the “Indenture”), among Domtar Corporation, a Delaware corporation (“Domtar”), Domtar Paper (as defined in Schedule E attached hereto) and The Bank of New York Mellon (formerly known as The Bank of New York), a New York banking corporation, as trustee (the “Trustee”);

(h) Each of the documents listed on Schedule G attached hereto (collectively, the “Supplemental Indentures”);

(i) The Registration Statement on Form S-3 (the “Registration Statement”), filed by Domtar, the Companies (as defined below) and the other registrants as provided on the signature pages thereto with the Securities and Exchange Commission on October 1, 2013, including a Prospectus, dated October 1, 2013 (the “Prospectus”), and as supplemented by a Preliminary Prospectus Supplement, dated November 20, 2013 (the “Prospectus Supplement”), relating to, inter alia, the securities described therein;

(j) Resolutions adopted by the board of directors of Domtar (the “Domtar Board”), dated September 27, 2013;

(k) Resolutions adopted by the Finance Committee of the Domtar Board, dated November 20, 2013;

(l) A certificate of an officer of each of the Companies, each dated November 26, 2013, as to certain matters;

(m) A certificate of an officer of Domtar, dated November 26, 2013, as to certain matters; and

(n) A Certificate of Good Standing for each of the Companies, each dated November 26, 2013, obtained from the Secretary of State.

Initially capitalized terms used herein and not otherwise defined are used as defined in the Indenture. The Corporations and the LLCs are referred to herein collectively as the “Companies.” The Indenture and the Supplemental Indentures are hereinafter referred to collectively as the “Transaction Documents.”

For purposes of this opinion, we have not reviewed any documents other than the documents listed in paragraphs (a) through (n) above. In particular, we have not reviewed any document (other than the documents listed in paragraphs (a) through (n) above) that is referred to in or incorporated by reference into any document reviewed by us. We have assumed that there exists no provision in any document that we have not reviewed that is inconsistent with the opinions stated herein. We have conducted no independent factual investigation of our own but rather have relied solely upon the foregoing documents, the statements and information set forth therein and the additional matters recited or assumed herein, all of which we have assumed to be true, complete and accurate in all material respects.

To Each of the Persons Listed

  on Schedule A Attached Hereto

November 26, 2013

Page 3

With respect to all documents examined by us, we have assumed that (i) all signatures on documents examined by us are genuine, (ii) all documents submitted to us as originals are authentic, and (iii) all documents submitted to us as copies conform with the original copies of those documents.

For purposes of this opinion, we have assumed (i) that any amendment or restatement of any document reviewed by us has been accomplished in accordance with, and was permitted by, the relevant provisions of said document prior to its amendment or restatement from time to time, (ii) except to the extent provided in paragraphs 1 and 5 below, the due organization, formation or creation, as the case may be, and valid existence in good standing of each party to the documents examined by us under the laws of the jurisdiction governing its organization, formation or creation, (iii) the legal capacity of natural persons who are signatories to the documents examined by us, (iv) except to the extent provided in paragraphs 2, 4, 6 and 8 below, that each of the parties to the documents examined by us has the power and authority to execute and deliver, and to perform its obligations under, such documents, and (v) except to the extent provided in paragraphs 3 and 7 below, the due authorization, execution and delivery by all parties thereto of all documents examined by us. We have not participated in the preparation of the Registration Statement, the Prospectus or the Prospectus Supplement and assume no responsibility for their contents.

This opinion is limited to the laws of the State of Delaware (excluding the insurance, securities and blue sky laws of the State of Delaware), and we have not considered and express no opinion on the laws of any other jurisdiction, including federal laws and rules and regulations relating thereto. Our opinions are rendered only with respect to Delaware laws and rules, regulations and orders thereunder that are currently in effect.

Based upon the foregoing, and upon our examination of such questions of law and statutes of the State of Delaware as we have considered necessary or appropriate, and subject to the assumptions, qualifications, limitations and exceptions set forth herein, we are of the opinion that:

1. Each of the Corporations has been duly incorporated and is validly existing in good standing as a corporation under the General Corporation Law of the State of Delaware (8 Del.C. §101, et seq.) (the “DGCL”).

2. Each of the Corporations has all necessary corporate power and authority under the DGCL, its Certificate of Incorporation and its Bylaws to execute and deliver, and to perform its obligations under, the Transaction Documents to which it is a party.

To Each of the Persons Listed

  on Schedule A Attached Hereto

November 26, 2013

Page 4

3. The execution and delivery by each of the Corporations of the Transaction Documents to which it is a party, and the performance by each of the Corporations of its obligations thereunder, have been duly authorized by all necessary corporate action on the part of such Corporation under the DGCL, its Certificate of Incorporation and its Bylaws.

4. Each of the Corporations has all necessary corporate power and authority under the DGCL, its Certificate of Incorporation and its Bylaws to execute the Registration Statement and to file the Registration Statement with the Securities and Exchange Commission.

5. Each of the LLCs has been duly formed and is validly existing in good standing as a limited liability company under the Delaware Limited Liability Company Act (6 Del. C. § 18-101, et seq.) (the “LLC Act”).

6. Each of the LLCs has all necessary limited liability company power and authority under the LLC Act and its LLC Agreement to execute and deliver, and to perform its obligations under, the Transaction Documents to which it is a party.

7. The execution and delivery by each of the LLCs of the Transaction Documents to which it is a party, and the performance by each of the LLCs of its obligations thereunder, have been duly authorized by all necessary limited liability company action on the part of such LLC under the LLC Act and its LLC Agreement.

8. Each of the LLCs has all necessary limited liability company power and authority under the LLC Act and its LLC Agreement to execute the Registration Statement and to file the Registration Statement with the Securities and Exchange Commission.

We note that notwithstanding any covenants to the contrary contained in the Transaction Documents: (i) the stockholders of any of the Corporations may dissolve such Corporation under Section 275(c) of the DGCL upon the consent of all the stockholders entitled to vote thereon, (ii) a stockholder owning at least 90% of the outstanding shares of each class of stock of any of the Corporations entitled to vote thereon may effect a merger with such Corporation under Section 253 or Section 267 of the DGCL, (iii) the stockholders of each of the Corporations may amend the Bylaws of such Corporation, and (iv) a member or manager of any of the LLCs has the right or power to apply to or petition a court to decree a dissolution of such LLC pursuant to Section 18-802 of the LLC Act.

We consent to the filing of this opinion with the Securities and Exchange Commission as an exhibit to Domtar’s Current Report on Form 8-K filed on or about November 26, 2013. We also consent to Debevoise & Plimpton LLP’s relying as to matters of Delaware law upon this opinion in connection with an opinion to be rendered by it on the date hereof. In addition, we hereby consent to the use of our name under the heading “Legal matters” in the Prospectus Supplement. In giving the foregoing consents, we do not thereby admit that we come within the category of Persons whose consent is required under Section 7 of the Securities Act of

To Each of the Persons Listed

  on Schedule A Attached Hereto

November 26, 2013

Page 5

1933, as amended, or the rules and regulations of the Securities and Exchange Commission thereunder. Except as stated above, without our prior written consent, this opinion may not be furnished or quoted to, or relied upon by, any other Person for any purpose.

WAY/MYK

Schedule A

Attends Healthcare Products, Inc.

Domtar AI Inc.

Domtar Delaware Investments Inc.

Domtar Personal Care Absorbent Hygiene Inc.

E. B. Eddy Paper, Inc.

EAM Corporation

Associated Hygienic Products LLC

Domtar Paper Company, LLC

Domtar A.W. LLC

Domtar Delaware Holdings, LLC

Domtar Industries LLC

Schedule B

Attends Healthcare Products, Inc.

Domtar AI Inc.

Domtar Delaware Investments Inc.

Domtar Personal Care Absorbent Hygiene Inc.

E. B. Eddy Paper, Inc.

EAM Corporation

Schedule C

Associated Hygienic Products LLC

Domtar Paper Company, LLC

Domtar A.W. LLC

Domtar Delaware Holdings, LLC

Domtar Industries LLC

Schedule D

Schedule E

Schedule F

Schedule G