At 11:30 Monday morning, writer Tammy Fortin set up her manual Olivetti in the grand marble atrium at Cantor Arts Center and began tapping out a short story. [...] artist Hope Gangloff set up her acrylic paints and began painting a portrait of Fortin as she typed. The main entrance to the Stanford University museum, built in 1894, has been converted into Gangloff’s studio as the first in a five-year series called the Diekman Contemporary Commissions Program, underwritten by arts benefactors John and Sue Diekman. There is a lot to tell because Gangloff, 42, lives in Brooklyn, N.Y., and drove out in her Subaru with her boxer mutt Olly, and all her paints and brushes and buckets. “She’s a fun challenge,” says Gangloff, as Fortin clacks away in single space, working that carriage return, her salt-and-pepper hair blending nicely with the marble wall behind her. The typewriter sits on a pullout tray at a midcentury metal office desk. Scattered around are a metal lunch box in red tartan, a bottle of Wite-Out, a magnifying glass and any number of dictionaries and art history books open for quick reference, plus a Princess dial phone with the receiver off the hook and dangling to the floor so she won’t be distracted by a caller. There is a lot of detail to capture, and those who can’t wait around to see the finished product can go upstairs where the concurrent show “Hope Gangloff Curates Portraiture” is on the balcony. There is a whole wall of portraits, and visitors can turn around and lean over the railing to see the next one being worked on at the bottom of the stairs. “Hope is an incredibly talented painter who evokes the 19th and 20th century masters and updates the tradition, ” says Carty.