Click both for bigger.
This is a strange shirt. It's a short-sleeved polo shirt made from what appears to be a thin cotton/poly blend. There is no label, which leads me to believe it's either homemade or maybe was created in-house at Universal. I love the callousness with which the pocket was just carelessly smacked on without a care in the world for matching the pattern.
One peculiar thing about the graphic is that the background pattern features the official art with Lindsey Wagner, but the vignettes don't resemble her even slightly. This leads me to date the shirt pretty confidently to 1976, possibly before the show aired and definitely before Wagner was more established as the character.
What's really puzzling is this: if this is a homemade shirt, that means somebody actually manufactured and marketed this fabric! It's not bed sheet material, so its purpose is a little baffling. That's what makes me think it may have been made within the studio. It's hard to imagine there being much of a market for this material. Weird!
Here's another view of the pattern:
Side note: obviously I fixed my scanner! I have an old Microtek model, and they totally abandoned Mac support for the last few years, so the software got increasingly buggy with each Mac OS upgrade. Finally, recently, I installed Adobe CS5 and it somehow totally broke what was left of the terrible Microtek software. I thought I was going to have to buy a new scanner, which infuriated me since nothing was wrong with the old one. Luckily a coworker knew the solution: Vuescan to the rescue! I owe you big time, David.