If using a font that is highly contrasted (on glass) – meaning the font is thick on one side and thin on the other – then a 0.25- to 0.5-point stroke is necessary. The font size for this can start at just over 1/16″ around 8 points.
When working with small fonts like government warning labels on the backs of wine bottles, the smallest size should be around 8 points (just over 1/16″) using a 0.25-point stroke on the lettering if you are not using the bold version of any font. Bold versions of some fonts don’t need to be touched up.
—Rayzist
