Definition
Per sample (also rendered "by sample") is a term of commercial law describing a sale or purchase in which the goods to be delivered are warranted to conform in quality, character, or kind to a sample exhibited by the seller at the time of contracting. The transaction creates an implied or express collateral undertaking — distinct from the main obligation of delivery — that the bulk of the goods will match the sample shown. If the goods delivered differ materially from the sample, the buyer has grounds to reject the tender or seek damages for breach of warranty.
The term operates as a qualifier on the nature of the seller's obligation: rather than warranting goods by description alone, the seller's duty is measured against a physical standard both parties have inspected.
Common Confusion
Per sample should not be confused with sale by description. A sale by description relies on words — specification sheets, catalog entries, labeling — to define what is owed. A sale per sample relies on an actual specimen exhibited before or at the time of contracting. The two are not mutually exclusive; a sale may be both by sample and by description, in which case the goods must conform to both standards. Courts and historical sources sometimes blur the distinction, so researchers reading older cases should check which mode of warranty the court is actually analyzing.
Per sample should also be distinguished from inspection sales, where the buyer has examined the full lot itself (not a representative sample) and accepts it as seen. In an inspection sale, the buyer's acceptance of the goods after examination generally waives quality warranties; in a per sample sale, the buyer has seen only a specimen and retains warranty rights as to the bulk.
Why It Matters in Research
The term surfaces most often in nineteenth- and early twentieth-century commercial litigation concerning commodity trades — grain, cotton, wool, manufactured cloth, hardware — where samples were routinely exchanged at trade fairs or through brokers. Researchers working in this period should be alert to several things.
First, the warranty created by a per sample sale was treated by many courts as a collateral warranty, meaning it survived acceptance of the goods and could ground a separate action even after the buyer had taken delivery. This is the significance of the "collateral engagement" language in Bouvier. Researchers should not assume a buyer's receipt of goods forecloses a per sample warranty claim in historical cases.
Second, the governing law shifted substantially over the course of the twentieth century. Uniform Sales Act jurisdictions (pre-UCC states) developed a body of per sample case law that does not map cleanly onto UCC Article 2, which addresses sample sales in § 2-313 (express warranties by sample or model) and § 2-317 (cumulation and conflict of warranties). Researchers using pre-UCC cases to interpret modern disputes must account for this doctrinal transition.
Third, the distinction between a "sample" and a "model" carries legal consequence under the UCC: a sample is drawn from the actual goods to be sold, while a model is an exhibit not drawn from the contract lot. Historical sources predate this terminological precision and use "sample" loosely to cover both.
Fourth, international commercial research requires additional care. Sale by sample is addressed in the Vienna Convention on Contracts for the International Sale of Goods (CISG) through its conformity provisions (Art. 35), though the Convention does not use the phrase "per sample" as a term of art.
Historical Dictionary Support
Bouvier's is the sole historical dictionary source available for this entry. Its treatment is brief: a purchase per sample is characterized as a "collateral engagement that the goods shall be of a particular quality," citing 4 B. & Ald. 387 — a reference to the English King's Bench reporter Barnewall and Alderson, indicative of the term's roots in early nineteenth-century English mercantile law. The "collateral" framing is analytically significant and appears designed to preserve a warranty action independent of the main contract of sale.
Bouvier offers no elaboration on the mechanics of conformity, the scope of permissible variation, or buyer's remedies — gaps that are filled, in the historical record, by treatises on the law of sales (Blackburn on Sales, Benjamin on Sales) and by the accumulated commodity-trade case law of American and English courts. Researchers who rely on Bouvier alone will have only the threshold concept; the operative doctrine lives in case law.
Jurisdictional Note
Under American law, per sample warranty doctrine is now primarily governed by UCC Article 2, adopted with variations across all U.S. states. Louisiana's distinct sales law framework applies different conformity rules. International sales governed by the CISG apply Article 35 conformity standards, which overlap substantially with but are not identical to UCC warranty doctrine.