Proto Labs Inc — Director's Dealing 2013

May 2, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Proto Labs Inc (PRLB)
CIK: 0001443669
Period of Report: 2013-04-30

Reporting Person: Smith Brian K (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-04-30	Common Stock	S	43539	$50.22	Disposed	100738	Direct
2013-04-30	Common Stock	S	6461	$51.02	Disposed	94277	Direct
2013-05-01	Common Stock	G	100	$0.00	Disposed	94177	Direct
2013-05-02	Common Stock	S	14000	$51.1244	Disposed	80177	Direct

Footnotes

F1: Reflects the weighted average price of 43,539 shares of common stock of Proto Labs, Inc. sold by the reporting person in multiple transactions on April 30, 2013 with sale prices ranging from $50.00 to $50.99 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

F2: Reflects the weighted average price of 6,461 shares of common stock of Proto Labs, Inc. sold by the reporting person in multiple transactions on April 30, 2013 with sale prices ranging from $51.00 to $51.10 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

F3: Reflects the weighted average price of 14,000 shares of common stock of Proto Labs, Inc. sold by the reporting person in multiple transactions on May 2, 2013 with sale prices ranging from $51.10 to $51.15 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.