Mainframe Studios, which houses affordable workspaces for artists and low-cost office space for nonprofit arts groups, has completed renovations that added 58 studios on the third floor at its location at 900 Keosauqua Way in Des Moines. The studio now has 131 workshops, 97% of which are occupied. “We had an extensive waitlist to pull from with artists waiting years for space while we raised funds for renovations,” Mainframe Studios director Siobhan Spain said in a prepared statement. “We’re playing matchmaker for the final spaces and expect to have them rented soon.” Mainframe Studios will host its regular First Friday event from 4 to 8 p.m. Friday at the studio. The public is invited to help celebrate the unveiling of the third floor. Festivities will include a kinetic sculpture installation by Daniel Nutt; communal robotic paintings with Amenda Tate; a showcase of DeAn Kelly’s Writing History project with Oakridge Neighborhood; music by RunDSM Deejay Charles Walker; and food and drink by Tangerine Food Co. The event is free and reservations can be made by visiting www.mainframestudios.org.