United States securities and exchange commission logo March 31, 2022 Daniel Schumacher Interim Chief Financial Officer Proto Labs Inc 5540 Pioneer Creek Drive Maple Plain, Minnesota 55359 Re: Proto Labs Inc Form 10-K for the Year Ended December 31, 2021 Filed February 18, 2022 File No. 001-35435 Dear Mr. Schumacher: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Manufacturing