<SEC-DOCUMENT>0001209191-12-014715.txt : 20120301
<SEC-HEADER>0001209191-12-014715.hdr.sgml : 20120301
<ACCEPTANCE-DATETIME>20120301193657
ACCESSION NUMBER:		0001209191-12-014715
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120229
FILED AS OF DATE:		20120301
DATE AS OF CHANGE:		20120301

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:		12659735

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DAMORE RICHARD A
		CENTRAL INDEX KEY:			0001206641

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		12659736

	MAIL ADDRESS:	
		STREET 1:		C/O NORTHBRIDGE VENTURE PARTNERS
		STREET 2:		950 WINTER ST STE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ANDERSON EDWARD T
		CENTRAL INDEX KEY:			0001218581

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		12659737

	MAIL ADDRESS:	
		STREET 1:		950 WINTER ST SUITE 4600
		CITY:			WATHAM
		STATE:			MA
		ZIP:			02451

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NORTH BRIDGE GROWTH EQUITY I LP
		CENTRAL INDEX KEY:			0001390657

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		12659733

	BUSINESS ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		7812900004

	MAIL ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NBGE Manager, LLC
		CENTRAL INDEX KEY:			0001542779
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		12659738

	BUSINESS ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02454
		BUSINESS PHONE:		781-290-0004

	MAIL ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02454

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NBGE GP, LLC
		CENTRAL INDEX KEY:			0001542781
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		12659734

	BUSINESS ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02454
		BUSINESS PHONE:		781-290-0004

	MAIL ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02454

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			North Bridge Growth Management, L.P.
		CENTRAL INDEX KEY:			0001542785
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35435
		FILM NUMBER:		12659732

	BUSINESS ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02454
		BUSINESS PHONE:		781-290-0004

	MAIL ADDRESS:	
		STREET 1:		950 WINTER STREET
		STREET 2:		SUITE 4600
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02454
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-02-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001542779</rptOwnerCik>
            <rptOwnerName>NBGE Manager, LLC</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>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218581</rptOwnerCik>
            <rptOwnerName>ANDERSON EDWARD T</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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001206641</rptOwnerCik>
            <rptOwnerName>DAMORE RICHARD 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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <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>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001542781</rptOwnerCik>
            <rptOwnerName>NBGE GP, LLC</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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001390657</rptOwnerCik>
            <rptOwnerName>NORTH BRIDGE GROWTH EQUITY I LP</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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001542785</rptOwnerCik>
            <rptOwnerName>North Bridge Growth Management, L.P.</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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-02-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5991790</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5991790</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By North Bridge Growth Equity I, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-02-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>430000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>16.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6421790</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By North Bridge Growth Equity I, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series A Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2012-02-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>427985</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5991790</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By North Bridge Growth Equity I, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Upon the closing of the Issuer's initial public offering, each of the 427,985 shares of Series A Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 14-for-1 basis.</footnote>
        <footnote id="F2">Represents shares held directly by North Bridge Growth Equity I, L.P. NBGE Manager, LLC (&quot;NBGE&quot;) 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. Douglas 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, Mr. Anderson and Mr. D'Amore each disclaim any beneficial ownership of such shares, except to the extent of any pecuniary interest therein. This report shall not be deemed an admission that any of the reporting persons is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F3">The security does not have an expiration date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/c/ Catherine M. Verschelden, Attorney-in-Fact for NBGE Manager, LLC</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Catherine M. Verschelden, Attorney-in-Fact for Edward Anderson</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Catherine M. Verschelden, Attorney-in-Fact for Richard D'Amore</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Catherine M. Verschelden, Attorney-in-Fact for Douglas Kingsley</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Catherine M. Verschelden, Attorney-in-Fact for NBGE GP, LLC</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Catherine M. Verschelden, Attorney-in-Fact for North Bridge Growth Equity I, L.P.</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Catherine M. Verschelden, Attorney-in-Fact for North Bridge Growth Management, L.P.</signatureName>
        <signatureDate>2012-03-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
