SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* NBGE Manager, LLC (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 02/23/2012	3. Issuer Name and Ticker or Trading Symbol Proto Labs Inc [ PRLB ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Preferred Stock	(1)	(2)	Common Stock	5,991,790	(1)	I	By North Bridge Growth Equity I, L.P.(3)

1. Name and Address of Reporting Person* NBGE Manager, LLC (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ANDERSON EDWARD T (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* DAMORE RICHARD A (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NBGE GP, LLC (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* North Bridge Growth Management, L.P. (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NORTH BRIDGE GROWTH EQUITY I LP (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* KINGSLEY DOUGLAS A (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 (Street) WALTHAM MA 02454 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Each of the 427,985 shares of Series A Preferred Stock is convertible at any time at the option of the holder, and will automatically convert into shares of the Issuer's Common Stock on a 14-for-1 basis in connection with the closing of the Issuer's initial public offering. The number of shares of Common Stock reported on this Form 3 reflects the conversion of all shares of Series A Preferred Stock into shares of Common Stock on a 14-for-1 basis.

2. The security does not have an expiration date.

3. Represents shares held directly by North Bridge Growth Equity I, L.P. NBGE Manager, LLC ("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 dispostive 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.

Remarks:

	/s/ Catherine M. Verschelden, Attorney-in-Fact for NBGE Manager, LLC	02/23/2012
	/s/ Catherine M. Verschelden, Attorney-in-Fact for Edward Anderson	02/23/2012
	/s/ Catherine M. Verschelden, Attorney-in-Fact for Richard D'Amore	02/23/2012
	/s/ Catherine M. Verschelden, Attorney-in-Fact for NBGE GP, LLC	02/23/2012
	/s/ Catherine M. Verschelden, Attorney-in-Fact for North Bridge Growth Management, L.P.	02/23/2012
	/s/ Catherine M. Verschelden, Attorney-in-Fact for North Bridge Growth Equity I, L.P.	02/23/2012
	/s/ Catherine M. Verschelden, Attorney-in-Fact for Douglas Kingsley	02/23/2012
	** Signature of Reporting Person	Date
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