<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2009-06-25</periodOfReport>

    <dateOfOriginalSubmission>2009-06-29</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000077597</issuerCik>
        <issuerName>SPARTECH CORP</issuerName>
        <issuerTradingSymbol>SEH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001229521</rptOwnerCik>
            <rptOwnerName>ANDY RALPH B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SPARTECH CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>120 S. CENTRAL AVENUE, SUITE 1700</rptOwnerStreet2>
            <rptOwnerCity>CLAYTON</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>63105</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>75484</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>350261</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Corporation / Limited Partnership</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Reporting person owns 100% of the common stock in a corporation which owns a .1% general partnership interest in a limited partnership.  The limited partnership owns 350,261 shares of Spartech Corporation common stock.

The reporting person has sole investment and voting power over these shares as President and sole shareholder of the corporation which is general partner of the limited partnership.  As such the reporting person is reporting 100% of the holdings of the limited partnership pursuant to Instruction 4(b)(iv) of Form 4.

This amended Form 4 is being filed to remove the grant of restricted stock units that was incorrectly reported as being granted to Mr. Andy on June 25, 2009.  Pursuant to his appointment as Chairman of the Board on January 2, 2008, Mr. Andy was granted a one-time award of 69,882 shares of restricted stock and agreed to forego all other cash and non-cash compensation for the remainder of 2008, 2009 and 2010.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Randy C. Ridenhour, Power of Attorney for Ralph B. Andy</signatureName>
        <signatureDate>2009-06-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
