EDIT: Added a small Test file to quickly print a piece of the bracket. Use that to test the fit on a cabinet.
This towel ring fits a buyer-assembled Mainstays Kitchen Island Cart, but it should fit a lot of other flush-mount cabinet doors if there's adequate gap above the door.
The bracket is a close fit on a door which is 0.7" (~17.5mm) thick, with an upper gap of 0.15" (~4mm) but might be adjusted with design software, such as Blender, or if the print software allows it XYZ scaliing might adjust the fit.
Almost nothing touches the build platform so there's no need for a raft. And little strength is required so minimum fill is ok. I got adequate print quality with 0.30mm layers and average speed.
60 minutes, 30grams ABS.
Free the ring with a thin blade or tool.
[edit 8-2018; These earlier projects lacked Metric files. At the time, I was unaware that some software could not determine the actual size if a project was designed in inches. If your software imports an impossibly tiny file, just scale it up XY+Z by a factor of 25.4. (There are 25.4 millimeters to the inch.)