Type

A sign has to work at a distance and often in a short time. The typography is doing a different job from typography on a page.

Letter height, contrast with the background, and the number of words matter more than a fine difference between two text faces. A condensed face can fit a long name on a narrow fascia and still fail if it is used at a size the passing reader cannot resolve. Paint, vinyl, and a light box each change how the edge of a letter looks; a drawing that was sharp on screen can look heavy once it is cut or painted.

If a sign is bilingual, the two scripts may need different sizes to look evenly weighted. That is a matter of looking, not of applying a single ratio to every pair of languages. Stand where the sign is meant to be read, if you can, before you decide that the drawing is finished.

This page does not offer a standard signage typeface. Licensing, the making method, and the viewer's distance should decide that choice for each job.