For a San Francisco event, DTF (direct-to-film) handles full-color art and a different name on every shirt, and screen printing is the fast, durable choice when one simple design goes on hundreds of shirts. Plenty of events run both from one station.
DTF transfers
The art prints onto film first, then a heat press moves it onto the shirt. There's no screen to burn, so there's no color limit and the design can change from one guest to the next. At a developer conference that means a handle or a team name on each shirt. At a Mission Bay biotech mixer it means a detailed logo with gradients that would take four screens. See live DTF printing.
Screen printing
Ink goes through a mesh screen, one screen per color. Once the screens are set it's quick, and the print is heavy and holds up. It suits bold one- to three-color art repeated all day, like a sponsor shirt on a Moscone show day or a festival design at Fort Mason. See live screen printing.
If the room is engineers and founders, personalization usually wins, and that points to DTF. If it's a festival line or a conference with one sponsor design, screens keep up better. When a San Francisco event needs both, we run both from one station.