Shown here is a close up of the smallest and largest Prismic emb'd No.9's I have found so far. This style of engraved emb'g was adopted around 1895, and replaced by the less labor-intensive industrial stamps that make up 99% of all dated No.9 production. There is a huge number of variations within the prismic style, and apparently letter size was not near as important as having that tight, concise lettering style!