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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   NBGE Manager, LLC 2. Date of Event Requiring Statement (Month/Day/Year) 02/23/2012 3. Issuer Name and Ticker or Trading Symbol Proto Labs Inc [PRLB] (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY, 950 WINTER STREET, SUITE 4600 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 Original Filed(Month/Day/Year) (Street) WALTHAM, MA 02454 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) 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)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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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 of Derivative Security: 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)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
NBGE Manager, LLC C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	  X	  X	Â	Â
ANDERSON EDWARD T C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	Â	  X	Â	Â
DAMORE RICHARD A C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	Â	  X	Â	Â
NBGE GP, LLC C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	Â	  X	Â	Â
North Bridge Growth Management, L.P. C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	Â	  X	Â	Â
NORTH BRIDGE GROWTH EQUITY I LP C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	Â	  X	Â	Â
KINGSLEY DOUGLAS A C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA 02454	  X	Â	Â	Â

Signatures

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

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(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.

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