## Facts

- Steinfur Patents Corporation owned two related patents issued to the same inventor, both based on applications filed May 3, 1924, concerning treatment of naturally dark fur skins to permit bleaching and (optionally) dyeing into commercially desirable colors.
- The patents were: (1) a **product patent**, U.S. Patent No. **1,564,378** (issued Dec. 8, 1925), and (2) a **process patent**, U.S. Patent No. **1,573,200** (issued about two months later).
- The patents addressed a problem in the fur industry: dark skins were less expensive, but prior methods could not reliably bleach them for dyeing into lighter shades **without damaging** the leather or the hair.
- The disclosed process had three general stages:
  - A **pre-treatment** soaking step using a “protective agent” (for example, **ferrous sulphate**), preferably also including a “stabilizing agent” (for example, **ammonium chloride**);
  - A **bleaching** step in a bath with a bleaching agent (for example, **hydrogen peroxide**); and
  - Optional **dyeing** of the bleached skins using customary dyeing methods.
- Steinfur sued William Beyer, Inc., and others in the Southern District of New York for infringement of both patents.
- The district court (reported at **56 F.2d 372**) held **all asserted claims** of both patents **valid and infringed**, and entered a decree for Steinfur.
- Defendants appealed to the United States Court of Appeals for the Second Circuit, attacking validity (especially of the product patent as allegedly outside statutory subject matter) and disputing infringement.

## Issues

1. Whether fur skins that have been chemically treated and bleached (and possibly dyed) by the patented method are patentable subject matter as a “manufacture,” or instead are an unpatentable natural material with only a changed appearance.
2. Whether the claimed process and the resulting treated-skin product reflected patentable invention over the prior art in bleaching and dyeing furs.
3. Whether defendants’ accused treatment method and resulting skins fell within the scope of the asserted claims, establishing infringement.

## Decision

- The Second Circuit **affirmed** the district court’s decree.
- The court sustained the **validity** of both the **process patent** and the **product patent**.
- The court sustained the district court’s **infringement** findings as to both patents.

## Legal Principles

- A product that begins as a natural material can be a patentable “manufacture” when human-applied chemical treatment gives it **new characteristics and utility** so that it is, in practical terms, a new article of commerce rather than the untreated natural material.
- When the prior art does not teach a claimed sequence and combination of steps that solves a technical problem (here, bleaching dark skins without injury and enabling profitable dyeing), the process and its resulting product may satisfy the then-required standard of “invention.”
- An appellate court will not overturn trial-level validity and infringement determinations where the record supports the findings and the lower court’s analysis is sound.

## Conclusion

The Second Circuit held that Steinfur’s coordinated chemical treatment method for dark fur skins—and the bleached/dyed skins produced by that method—were patentable and were infringed, affirming a decree that upheld both the process patent and the product patent on the ground that the treatment created a commercially distinct manufactured article capable of bleaching and dyeing without the damage that had limited prior techniques.


Steinfur Patents Corp. v. William Beyer, Inc., 62 F.2d 238, 16 U.S.P.Q. 219 (1932)