Trust

Sources & methodology

Everything on this site follows one rule: we publish what the sources support, we show where they disagree, and we omit what we can't verify. No page invents precision.

Curt Teich dating tables

The decoder's ranges come from the Guide to Dating Curt Teich Postcards, prepared by the Lake County Discovery Museum (2011) and published by the Newberry Library, which holds the Curt Teich Archives — roughly 2.5 million items and the company's own production records. Three apparent misprints in the source tables are corrected and disclosed on the decoder page. Where the guide itself marks dates as approximate (1908–1913, the two-letter series, the sparse C series), the decoder says so and returns ranges, not fake years.

Stamp box ranges

Stamp box dating is collector consensus, not company records, and we treat it that way. Our table is cross-checked across five references: the the2Buds.com chart as republished by Sports Collectors Daily; the SABR Baseball Cards Research Committee's guide; long-running collector charts; the Playle's quick-reference directory; and period comparisons. Where the references disagree — AZO squares-in-corners begins in 1925, 1926 or 1927 depending on who you read — the brand page shows the disagreement. Marks supported by only one reference are held back until corroborated.

Era boundaries

The six-era chronology follows the standard framework used by the Smithsonian Institution Archives and the collecting literature. Boundaries are US-specific where they derive from US postal rules; the pages say so.

Corrections

If you can show us a better-sourced range than the one we publish, we want it — that's how this reference improves. Errors are ours and we fix them.