 SANTA FE, NM ACCESSWIRE April 13, 2021 Sigma Labs, Inc. NASDAQ:SGLB Sigma Labs, a leading developer of quality assurance software for the commercial 3D metal printing industry, will hold a conference call on Thursday, April 22, 2021 at 4:30 p.m. Eastern time to discuss its results for the first quarter ended March 31, 2021. 