Note to Windy City graphic designers: this is your last day this year to see Helvetica, a documentary celebrating the 50th anniversary of this famous font. This writer’s friend bought tickets to tonight’s 8 p.m. show last night, only because the previous show was sold out. It’s hard to say whether there are any tickets at all left at this point, which is no surprise given the last time this charming documentary played at the Gene Siskel Center. If you can still manage to get in, here’s a synopsis: helvetica was invented by a Swiss designer in 1957, half a century later this typeface is everywhere on signs, advertisements, magazines, labels, film titles, and e-mail. Director Gary Hustwit turns the camera on the worldwide design community for their take on why you can’t get away from Helvetica virtually anywhere on this planet. Hear graphic designers include Massimo Vignelli, Matthew Carter, Eric Spiekermann, Wim Crouwel, and others speak if you can manage to squeeze into tonight’s screening. If not, you just might have to see this home video. Sorry!