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                                                                     EXHIBIT 2.1


                 AMENDMENT NO. 1 TO AGREEMENT AND PLAN OF MERGER

        This Amendment No. 1 (the "Amendment"), dated as of January 10, 2000, is
entered into by and among Photronics, Inc., a Connecticut corporation
("Parent"), AL Acquisition Corp., a California corporation and a wholly owned
subsidiary of Parent ("Merger Sub"), and Align-Rite International, Inc., a
California corporation (the "Company").

        WHEREAS, Parent, Merger Sub and the Company have previously executed and
delivered that certain Agreement and Plan of Merger, dated as of September 15,
1999, by and among Parent, Merger Sub and the Company (the "Merger Agreement");

        WHEREAS, Parent, Merger Sub and the Company desire to amend the Merger
Agreement as set forth herein and pursuant to Section 7.3 of the Merger
Agreement; and

        WHEREAS, the shareholders of Company who are party to the Voting
Agreement have reaffirmed the Voting Agreement in light of this Amendment.

        NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants and agreements herein contained, and intending to be legally bound
hereby, Parent, Merger Sub and Company hereby agree as follows:

        1. Definitions. Capitalized terms used herein but not expressly defined
shall have the meanings accorded such terms in the Merger Agreement.

        2. Amendment of Section 2.3 of the Merger Agreement. The first sentence
of Section 2.3 of the Merger Agreement is hereby amended and restated to read,
in its entirety, as follows:

              "At the Effective Time, by virtue of the Merger and without any
        action on the part of the holder of any shares of Company Common Stock
        or any shares of capital stock of Merger Sub, subject to this Section
        2.3 and Section 2.4(f), each share of Company Common Stock issued and
        outstanding immediately prior to the Effective Time (other than shares
        to be canceled in accordance with Section 2.2 (the "Canceled Shares")
        and Dissenting Shares) shall be converted into 0.85 (the "Conversion
        Number") of duly authorized, validly issued and nonassessable shares of
        Parent Common Stock (the "Merger Consideration"), provided that, if
        between the date of this Agreement and the Effective Time, the
        outstanding shares of Parent Common Stock shall have been changed into a
        different number of shares or a different class, by reason of any
        declared or completed stock dividend, subdivision, reclassification,
        recapitalization, split, combination or exchange of shares, the
        Conversion Number shall be adjusted correspondingly to the extent
        appropriate to reflect such stock dividend, subdivision,
        reclassification, recapitalization, split, combination or exchange of
        shares."

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              All references in the Merger Agreement to the Conversion Number or
        the Merger Consideration shall be deemed to refer to the Conversion
        Number or the Merger Consideration, as the case may be, as such terms
        are defined in this Amendment.

        3. Amendment of Section 3.11 of the Merger Agreement. Section 3.11 of
the Merger Agreement is hereby amended and restated to read, in its entirety, as
follows:

              "SECTION 3.11 Proxy Statement; Registration Statement; Other
        Information. None of the information with respect to the Company or its
        Subsidiaries to be included in the Proxy Statement (as defined in
        Section 5.2) or the Registration Statement (as defined in Section 5.2)
        will, in the case of the Proxy Statement or any amendments thereof or
        supplements thereto, at the time of the mailing of the Proxy Statement
        or any amendments or supplements thereto, and at the time of the Company
        Meeting (as defined in Section 5.3) or, in the case of the Registration
        Statement, at the time it becomes effective or at the time of any
        post-effective amendment, contain any untrue statement of a material
        fact or omit to state any material fact required to be stated therein or
        necessary in order to make the statements therein, in light of the
        circumstances under which they were made, not misleading, except that no
        representation is made by the Company with respect to information
        supplied in writing by Parent or any affiliate of Parent specifically
        for inclusion in the Proxy Statement. The Proxy Statement will comply as
        to form in all material respects with the provisions of the Exchange Act
        and the rules and regulations promulgated thereunder."

        4. Amendment of Section 3.14 of the Merger Agreement. Section 3.14 of
the Merger Agreement is hereby amended and restated to read, in its entirety, as
follows:

               "SECTION 3.14 Opinion of Financial Advisor. The Board of
               Directors of the Company has received an opinion of CIBC World
               Markets Corp., dated January 10, 2000, to the effect that, as of
               such date, the Exchange Ratio (as defined therein) is fair to the
               Company's shareholders from a financial point of view. A copy of
               the written opinion of CIBC World Markets Corp. will be delivered
               to Parent as soon as practicable after the date of this
               Agreement."

        5. Amendment of Section 4.3 of the Merger Agreement. Section 4.3(a) of
the Merger Agreement is hereby amended and restated to read, in its entirety, as
follows:

              "(a) Each of Parent and Merger Sub has full corporate power and
        authority to enter into this Agreement and to carry out its obligations
        hereunder. The execution and delivery of this Agreement and the
        consummation of the transactions contemplated hereby have been duly and
        validly authorized by the Boards of Directors of Parent and Merger Sub
        and by Parent as sole stockholder of Merger Sub, and no other corporate
        or stockholder proceedings on the part of Parent or Merger Sub are
        necessary to authorize this Agreement, the issuance of the Parent Common
        Stock and the other transactions contemplated hereby. This Agreement has
        been duly and validly executed and delivered by Parent and Merger Sub
        and, assuming this Agreement has been duly and validly executed and
        delivered by the other parties hereto, this Agreement constitutes the
        valid and binding agreements of Parent and Merger Sub, enforceable
        against each of them in

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        accordance with its terms (except insofar as enforceability may be
        limited by applicable bankruptcy, insolvency, reorganization, moratorium
        or similar laws affecting creditors' rights generally, or by principles
        governing the availability of equitable remedies). Other than in
        connection with or in compliance with the provisions of the CGCL, the
        Securities Act, the Exchange Act, the HSR Act, any non-United States
        competition, antitrust and investments laws and the securities or blue
        sky laws of the various states and other jurisdictions, and, other than
        the filing of this Agreement and a duly executed officers' certificate
        by each of the Company and the Merger Sub with the California Secretary
        of State and any necessary state filings to maintain the good standing
        or qualification of the Surviving Corporation (collectively, the "Parent
        Required Approvals"), no authorization, consent or approval of, or
        filing with, any governmental body or authority is necessary on the part
        of Parent or Merger Sub for the consummation by Parent or Merger Sub of
        the transactions contemplated by this Agreement, except for such
        authorizations, consents, approvals or filings, the failure to obtain or
        make which would not in the aggregate have a Material Adverse Effect on
        Parent or Merger Sub; provided that Parent makes no representation with
        respect to such of the foregoing as are required by reason or facts
        specifically pertaining to Company or any of its Subsidiaries."

        6. Amendment of Section 4.14 of the Merger Agreement. Section 4.14 of
the Merger Agreement is hereby amended and restated to read, in its entirety, as
follows:

                      "SECTION 4.14 Vote of Parent Shareholders. Neither the
               vote of the holders of the outstanding shares of Parent Common
               Stock nor of any other class of the capital stock of Parent is
               required to approve the issuance of Parent Common Stock in the
               Merger."

        7. Amendment of Section 4.15 of the Merger Agreement. Section 4.15 of
the Merger Agreement is hereby amended to read, in its entirety, as follows:

                      "SECTION 4.15 Opinion of Financial Advisor. The Board of
               Directors of Parent has received the opinion of Banc of America
               Securities LLC, dated January 10, 2000, to the effect that, as of
               such date, the Exchange Ratio (as defined therein) is fair from a
               financial point of view to Parent. A copy of the written opinion
               of Banc of America Securities LLC will be delivered to the
               Company as soon as practicable after the date of this Agreement."

        8. Amendment of Section 5.2 of the Merger Agreement. Subsections (a) and
(b) of Section 5.2 of the Merger Agreement are hereby amended and restated to
read, in their entirety, as follows:

              "(a) The Company will, as promptly as practicable following the
        date of this Agreement, prepare and file with the SEC, will use
        reasonable efforts to have cleared by the SEC and thereafter mail to its
        shareholders as promptly as practicable, a proxy statement that will be
        the same proxy statement/prospectus contained in the Registration
        Statement (as hereinafter defined) and a form of proxy, in connection
        with the vote of the Company's shareholders with respect to the matters
        contemplated hereby (such proxy statement/prospectus, together with any
        amendments thereof or supplements thereto, in

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        each case in the form or forms mailed to the Company's shareholders, is
        herein called the "Proxy Statement").

              (b) Parent will, as promptly as practicable following the date of
        this Agreement, prepare and file with the SEC a registration statement
        of the Parent on Form S-4 (such registration statement, together with
        all and any amendments and supplements thereto, being herein referred to
        as the "Registration Statement"). Such Registration Statement shall be
        used for the purposes of registering with the SEC the issuance of Parent
        Common Stock to holders of Company Common Stock in connection with the
        Merger. In addition, each of Parent and the Company will upon reasonable
        advance notice provide the other with all information and other data as
        may be reasonably requested by Parent or the Company, as the case may
        be, in connection with the preparation and filing of the Registration
        Statement and the Proxy Statement."

        9. Amendment of Section 5.3 of the Merger Agreement. Section 5.3 of the
Merger Agreement is hereby amended and restated to read, in its entirety, as
follows:

               "SECTION 5.3 Shareholders' Meeting. The Company shall, in
        accordance with applicable law and its articles of incorporation and by
        laws, duly call, give notice of, convene and hold a meeting (which, as
        may be duly adjourned, shall be referred to as the "Company Meeting") of
        its shareholders as soon as practicable for the purpose of approving by
        the holders of a majority of the outstanding shares of Company Common
        Stock this Agreement and the Merger (the "Company Shareholder
        Approval"). The Company agrees to use its reasonable best efforts to
        cause the Company Meeting to occur within forty-five (45) days after the
        date on which the Registration Statement becomes effective. The Company
        shall include in the Proxy Statement the recommendation of its Board of
        Directors that shareholders vote in favor of the Company Shareholder
        Approval, subject to the duties of the Board of Directors of the Company
        to make any further disclosure to the shareholders (which shall not,
        unless expressly stated, constitute a withdrawal or adverse modification
        of such recommendation) and to the right to change such recommendation
        or terminate this Agreement following receipt of a Superior Proposal (as
        defined in Section 5.10)."

        10. Amendment of Section 6.1 of the Merger Agreement. Section 6.1(b) of
the Merger Agreement is hereby amended and restated to read, in its entirety, as
follows:

              "(b)   The Company Shareholder Approval shall have been obtained;"

        11. Amendments of Section 7.1 of the Merger Agreement. All references in
subsections (c) and (e) of Section 7.1 of the Merger Agreement to "February 25,
2000" are hereby amended to read "March 31, 2000." Subsection (b) of Section 7.1
of the Merger Agreement is hereby amended and restated to read, in its entirety,
as follows:

              "(b) by Parent (provided that Parent is not then in material
        breach of any representation, warranty, covenant or other agreement
        contained herein), (i) upon a breach of any representation, warranty,
        covenant or agreement on the part of the Company set forth in this
        Agreement, or (ii) if any representation or

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        warranty of the Company shall have become untrue, in either case
        continuing ten (10) days following notice to the Company of such breach
        or untruth and of a nature such that the conditions set forth in Section
        6.2(a) or Section 6.2(b), as the case may be, would be incapable of
        being satisfied by March 31, 2000;"

        Subsection (g) of Section 7.1 of the Merger Agreement is hereby amended
and restated, in its entirety, to read: "[Intentionally Omitted]", and
subsection (j) of Section 7.1 of the Merger Agreement is hereby amended and
restated, in its entirety, to read as follows:

              "(j) by the Company if the Average Parent Price is less than
        $18.82."

        12. Amendment of Section 7.5(a) of the Merger Agreement. Section 7.5(a)
of the Merger Agreement is hereby amended and restated to read, in its entirety,
as follows:

              "(a) In the event (i) the Company terminates this Agreement
        pursuant to Section 7.1(h) or (ii) Parent terminates this Agreement
        pursuant to Section 7.1(b)(i) or 7.1(i), then the Company shall pay
        Parent an amount equal to $3,640,000 (the "Termination Fee") by wire
        transfer of immediately available funds upon the occurrence of such
        event, and as a condition to termination in the case of termination
        pursuant to Section 7.1(h). The Termination Fee shall be the sole remedy
        of Parent for any breach of any representation, warranty, covenant or
        agreement on the part of the Company set forth in this Agreement."

        13. Amendment of Section 8.3 of the Merger Agreement. Section 8.3 of the
Merger Agreement is hereby amended by adding the following as a new subsection
(d), renumbering the current subsections (d) through (l) as subsections (e)
through (m) and deleting the reference to "Average Parent Price" in renumbered
subsection (m):

              "(d) Average Parent Price" means the average of the daily average
        per share high and low sales prices of one share of Parent Common Stock
        as reported on the Nasdaq National Market (as reported in the New York
        City edition of The Wall Street Journal or, if not reported thereby,
        another authoritative source) for each of the 20 trading days ending on
        the third trading day prior to the Company Meeting (as defined in
        Section 5.3, so long as the Closing Date occurs within five business
        days of the Company Meeting or, if the Closing Date is more than five
        business days after the Company Meeting, the Closing Date) rounded to
        the nearest cent."

        Renumbered subsection (i) of Section 8.3 of the Merger Agreement is
hereby amended by adding the following at the end of that subsection:

        ; provided, however, that events, circumstances and prospects disclosed
        by the Company to Parent in the Company Disclosure Letter, as amended as
        of January 7, 2000, and any consequences thereof, shall not constitute
        or form the basis of a Material Adverse Change or Material Adverse
        Effect."

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        In addition, renumbered subsection (m) of Section 8.3 of the Merger
Agreement is hereby amended to delete the following defined terms: "Parent
Meeting," "Parent Shareholder Approval" and "Meetings" and to add the defined
term "Proxy Statement" and the accompanying section reference "5.2(a)". All
references to "Joint Proxy Statement" in the Table of Contents of the Merger
Agreement and in Section 4.11 of the Merger Agreement shall be to "Proxy
Statement."

        14. Authority.

            (a) Each of Parent and Merger Sub has full corporate power and
        authority to enter into this Amendment. The execution and delivery of
        this Amendment and the consummation by each of Parent and Merger Sub of
        the transactions contemplated by the Merger Agreement, as amended
        hereby, have been duly and validly authorized by the Boards of Directors
        of Parent and Merger Sub. This Amendment has been duly and validly
        executed and delivered by each of Parent and Merger Sub and constitutes
        the valid and binding obligation of each of Parent and Merger Sub,
        enforceable against each of Parent and Merger Sub in accordance with its
        terms (except insofar as enforceability may be limited by bankruptcy,
        insolvency, reorganization, moratorium or similar laws affecting
        creditors' rights generally, or by principles governing the availability
        of equitable remedies).

            (b) The Company has full corporate power and authority to enter into
        this Amendment. The execution and delivery of this Amendment and the
        consummation by the Company of the transactions contemplated by the
        Merger Agreement, as amended hereby, have been duly and validly
        authorized by the Board of Directors of the Company. This Amendment has
        been duly and validly executed and delivered by the Company and
        constitutes the valid and binding obligation of the Company, enforceable
        against the Company in accordance with its terms (except insofar as
        enforceability may be limited by bankruptcy, insolvency, reorganization,
        moratorium, or similar laws affecting creditors' rights generally, or by
        principles governing the availability of equitable remedies).

        15. Governing Law. This Amendment shall be governed by and construed in
accordance with the laws of the State of California, without regard to any
applicable conflicts of law.

        16. Counterparts; Effect. This Amendment may be executed in one or more
counterparts, each of which shall be deemed to be an original, but all of which
shall constitute one and the same agreement.

        17. Merger Agreement Confirmed. Except as amended hereby, the Merger
Agreement is ratified and confirmed in all respects. Each reference in the
Merger Agreement or any other related document to the Merger Agreement, the
Agreement or this Amendment shall be deemed to a reference to the Merger
Agreement as amended hereby.



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        IN WITNESS WHEREOF, Parent, Merger Sub and the Company have caused this
Amendment to be signed by their respective officers thereunto duly authorized,
all as of the date first written above.

                                   PHOTRONICS, INC.


                                   By:
                                       -----------------------------------------
                                       Name:       Michael J. Yomazzo
                                       Title:      Vice Chairman

                                   By:
                                       -----------------------------------------
                                       Name:       Jeffrey P. Moonan
                                       Title:      Executive Vice President
                                                   Finance and Administration

                                   AL ACQUISITION CORP.


                                   By:
                                       -----------------------------------------
                                       Name:       Michael J. Yomazzo
                                       Title:      President

                                   By:
                                       -----------------------------------------
                                       Name:       Jeffrey P. Moonan
                                       Title:      Vice President

                                   ALIGN-RITE INTERNATIONAL, INC.


                                   By:
                                       -----------------------------------------
                                       Name:       James L. Mac Donald
                                       Title:      Chairman of the Board,
                                                   Chief Executive Officer
                                                   and President

                                   By:
                                       -----------------------------------------
                                       Name:       Petar N. Katurich
                                       Title:      Vice President of Finance,
                                                   Chief Financial Officer

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