A lot of precision instruments for measuring angular dimensions are now sold. But for most people, half a degree angle accuracy is sufficient. I experimented more for myself with how the scale with divisions and font is printed on an FDM printer (this can be seen in the photo with samples) and settled on the option where the scale numbers are convex by 0.75 mm (5 layers 0.15 mm high) . Convex font tinted with a thin marker. Details in white - HIPS, black - PETG.