Reading a Vendor's Batch History

Short answer: One report is a data point. A series across separate lots and months is a record, and reading it as a sequence exposes things no individual certificate shows: gaps, abandonment, and whether the set has been curated.

Look at the dates before the numbers

Thirty reports dated within one month describe a single production period. The same thirty across a year describe an ongoing practice. When two sellers show similar counts, the date range is usually the more informative figure.

Gaps are the most readable signal

A testing programme that stops for eight months and resumes has a reason, and the reason is rarely published. A record that simply ends is a historical fact being presented as a current practice — check the most recent date before anything else.

Coverage against catalogue

Which products are tested matters as much as how many reports exist. A set concentrated on three popular items tells you a lot about those items and little about the rest of the range.

Variance is the honesty check

A long series with no weak result has either been fortunate or filtered. The larger the set, the less plausible that nothing ever fell below the line — so size and uniformity together are a warning rather than a reassurance.

Lot references are what make it a chain

Without a lot number tying each report to a production run, a series is a collection of unconnected samples. With one, a buyer can match a document to the item in hand, which is the only point at which any of this becomes personally checkable.

What we record

Count, date range, whether reports resolve on the laboratory's own portal, and whether any below-threshold result appears. We publish the range rather than only the total, because the total alone is the number easiest to make look good.