Those small glue spreaders print in a few minutes. There are four different comb sizes: 

• 8 teeth of 1,3 mm
• 8 teeth of 2 mm
• 6 teeth of 2 mm
• 9 teeth of 2 mm

The good news is that you can modify the FreeCAD file to your needs. It is fully parametric meaning that the width of the teeth, the height of the teeth, the space in between the teeth and the length of the brush all can be altered  by simply changing a number in the spreadsheet. Give it a try!

If you need a larger glue spreader take a look at this model: https://www.printables.com/model/86892-glue-spreader-parametric-freecad