Cutter width is selected based on character height and font style. In general, single stroke characters should have a stroke width that is approximately 12% of the character height. For example, a quarter inch (.250") letter should have a .030" tip (.250" × .12 = .030"). It may be desirable however to decrease tip width on condensed fonts and increase it on extended ones so the appearance is more proportional.

On multiple line fonts, the cutter tip size is frequently specified in the engraving software which eliminates the guesswork. Basically, the width of the tip should be such that there will be slight overlap on each pass in order to prevent ridges in the bottom of the cut. If, for example, you were engraving a three-line font and the desired stroke width was .090", you should use a .035" cutter rather than a .030" to achieve the overlap.