A "vintage sliding glass door bar" usually refers to a simple, often homemade security device like a wooden dowel or an old broomstick placed in the door's track to prevent forced entry, or sometimes decorative, antique-style hardware for barn doors, but most modern "bars" are heavy-duty metal security devices with adjustable lengths and finishes like brass or powder-coated steel, offering enhanced home security with a classic or industrial look, rather than true antique style.

What it might be (Vintage Context):

The "Stick": The most common "vintage" solution was a simple wooden dowel, broom handle, or even a shower rod cut to fit the door track, offering basic security and a rustic, DIY feel.

Decorative Hardware: It could also refer to ornate, antique-style pulls or locking mechanisms for French or barn-style sliding doors, often in materials like brass or dark metals, as seen in Etsy listings for vintage glass barn doors.