 MAPLE PLAIN, Minn.--BUSINESS WIRE--Proto Labs, Inc. NYSE: PRLB, a leading online and technology-enabled, quick-turn on-demand manufacturer, today announced financial results for the fourth quarter and full year ended December 31, 2020. Fourth Quarter 2020 Highlights include: Revenue for the fourth quarter of 2020 was 105.2 million, representing a 2.1 percent decline compared to revenue of 107.5 million in the third quarter of 2020. EBITDA margin was 19.1 percent of revenue in the fourth q 