I have recreated this model from scratch to add volume indicators: Laundry detergent scoop by Ben | Download free STL model | Printables.com
I have printed it in PLA with adjustable layer height to get the print time under 2h. Also, if you want to color the 30ml and 60ml indicators with a sharpie, you might want to change the extrusion direction. As can be seen in my pictures, the color leaks in between the layers. If you change the extrusion outward, the result should be nicer.
The author remixed this model.