I whipped up these simple signs up that work with label makers. If there's a good reason nobody has made these yet, I don't know what it is. Made to work with 1/2 inch up to 1 inch size labels and has configurable angle and width.
I included the default STL files for 40 -80mm signs at a 60 degree angle for 1/2 inch labels.
Update fixed a typo in customizer dropdown for angle, and removed $fn from being modified.