## Facts

- King-Seeley Thermos Co. owned multiple federal trademark registrations for “Thermos” for vacuum-insulated containers.
- Aladdin Industries, Inc., a competitor, sought to label and advertise its products using “thermos” or “thermos bottle.”
- King-Seeley’s early advertising (1907–1923) promoted “Thermos bottle” as the product’s name and tended to associate “thermos” with the product category rather than a single source.
- By about 1923, “thermos” had become widely used as a common descriptive term for vacuum-insulated containers.
- After 1923, King-Seeley began pairing “Thermos” with “vacuum” (e.g., “Thermos vacuum bottle”) and undertook policing efforts against descriptive use, but generic public usage persisted.
- Trial evidence, including survey and usage proof, showed a substantial majority of consumers used “thermos” to mean the product type, not a particular producer.

## Issues

1. Whether “thermos,” as used for vacuum-insulated containers, had become a generic (common descriptive) term such that it no longer functioned as a protectable trademark.
2. If the term was generic, what injunctive limits could be imposed to reduce consumer confusion and unfair competition while permitting competitors to use ordinary product terminology.

## Decision

- The Second Circuit affirmed the district court.
- The court held that “thermos” had become generic in the minds of the consuming public as a synonym for vacuum-insulated containers.
- The court approved relief allowing Aladdin to use “thermos” descriptively under restrictions designed to reduce confusion and prevent claims implying exclusivity (e.g., “genuine” or “original” thermos).
- The court accepted that King-Seeley could retain protection for source-identifying uses (such as certain composite or stylized branding) even though the standalone product name had fallen into common use.

## Legal Principles

- A term is generic when its primary significance to the consuming public is the product, not the producer; once generic, exclusive trademark rights in the term as a mark end.
- Consumer understanding controls genericness; trade recognition of a term as a mark and the owner’s enforcement efforts do not override proof that the public uses the term as the common product name.
- A trademark owner’s own marketing that uses a mark as the name of the product can contribute to genericness and loss of exclusivity.
- Courts may craft equitable relief that permits competitors’ descriptive use of a generic term while restricting presentation likely to cause confusion or suggest false exclusivity.

## Conclusion

The court concluded that “thermos” had entered the public domain as the common name for vacuum-insulated containers, limiting King-Seeley’s ability to bar competitors from descriptive use while allowing narrowly tailored restrictions to reduce confusion and misleading claims.


King-Seeley Thermos Co. v. Aladdin Indus., Inc., 321 F.2d 577 (2d Cir. 1963)