<SEC-DOCUMENT>0001209191-12-054350.txt : 20121121
<SEC-HEADER>0001209191-12-054350.hdr.sgml : 20121121
<ACCEPTANCE-DATETIME>20121121171528
ACCESSION NUMBER:		0001209191-12-054350
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20121121
FILED AS OF DATE:		20121121
DATE AS OF CHANGE:		20121121

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KINGSLEY DOUGLAS A
		CENTRAL INDEX KEY:			0001197537

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		121221809

	MAIL ADDRESS:	
		STREET 1:		C/O ADVENT INTERNATIONAL CORP
		STREET 2:		75 STATE ST 29TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02104

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Proto Labs Inc
		CENTRAL INDEX KEY:			0001443669
		STANDARD INDUSTRIAL CLASSIFICATION:	FABRICATED STRUCTURAL METAL PRODUCTS [3440]
		IRS NUMBER:				000000000

	BUSINESS ADDRESS:	
		STREET 1:		5540 Pioneer Creek
		CITY:			Maple Plain
		STATE:			MN
		ZIP:			55359
		BUSINESS PHONE:		763-479-7474

	MAIL ADDRESS:	
		STREET 1:		5540 Pioneer Creek
		CITY:			Maple Plain
		STATE:			MN
		ZIP:			55359
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-11-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001443669</issuerCik>
        <issuerName>Proto Labs Inc</issuerName>
        <issuerTradingSymbol>PRLB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001197537</rptOwnerCik>
            <rptOwnerName>KINGSLEY DOUGLAS A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NORTH BRIDGE GROWTH EQUITY</rptOwnerStreet1>
            <rptOwnerStreet2>950 WINTER STREET, SUITE 4600</rptOwnerStreet2>
            <rptOwnerCity>WALTHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02454</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-11-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1417500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3404290</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By North Bridge Growth Equity I, L.P.</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4976</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares held directly by North Bridge Growth Equity I, L.P. NBGE is the managing manager of NBGE GP, LLC, which is the sole general partner of North Bridge Growth Management, L.P., which is the sole general partner of North Bridge Growth Equity I, L.P. NBGE has sole vesting and dispositive power over such shares. Mr. Kingsley, a director of the Issuer, is a founding managing director of NBGE GP, LLC. Shared voting and investment power over such shares is vested in the managers of NBGE, Edward Anderson and Richard D'Amore. Mr. Kingsley disclaims any beneficial ownership of such shares, except to the extent of any pecuniary interest therein. This report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F2">This transaction is also reported on a separate Form 4 filed by North Bridge Growth Equity I, L.P. on November 21, 2012.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Julie M. Regnier, Attorney-in-Fact for Douglas Kingsley</signatureName>
        <signatureDate>2012-11-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
