| System | Period | Rows | What it dates |
|---|---|---|---|
| Robeson Cutlery Works — the stamp and the firm's years of operation | c. 1907 → at least 1991 | 1 | The only printed point is the firm's years of operation per iKnife (Goins): ca. 1907 — at least 1991. There is no “stamp → year” table; an exact year |
| Grind, spine, scales, etching — era markers of a straight razor | 1700s → mid-1900s | 16 | Shared layer for all straight razors: it does not date precisely, but it cuts off an era. All rows are printed wordings from a shop-page guide review |