What a test report contains

Short answer: A test report must say who tested, what was tested, by which method and what number came out. Without all four parts the report is of no use. The report applies only to the batch that was tested and at the time it was done.

Four parts must be included

A usable test report says who tested, what was tested, by which method and what number came out. If one of the four is missing, the report is hard to use. A number without a sender, a sample or a method cannot be checked, and then it is mostly a promise.

Who tested

The report must name the laboratory that made the measurement. That makes it possible to see whether the laboratory is known and controlled, and to contact it if something is unclear. A report without a sender is like an anonymous claim and does not show whether anyone stands behind the work.

The sample must be identifiable

It states which batch, colour and quality the sample came from. Otherwise you do not know what the number applies to. A report on a white item does not automatically say anything about the same item in another colour, since another colour need not give the same result, so the sample must be described precisely.

What was tested

The report must say what was measured, such as the share of a fibre, the strength of the fabric or shrinkage in the wash. That only makes sense once you know what the number is about. A vague heading like quality is too loose, so a good report is concrete about which property was examined.

The method has a number

Standards have numbers. The number makes it possible to see exactly how the measurement was made. If you know the method, you can compare one report with another made to the same standard, and you can see whether two numbers can be compared at all. See Egtved.

The result has a unit

A number without a unit says nothing. It must say grams, percent, newtons or whatever is being measured in. Without the unit you cannot know whether a number is large or small, and you cannot compare it with a requirement. See Zent and Decoy.

How long is a typical report

From a single page to many, depending on how many tests were made. A report on one single matter can fit on a page, while a full investigation with many measurements takes more space. Length therefore says nothing about quality. What matters is that the four parts are present and clear.

Can a customer get the report

Rarely directly, but the shop can say what it covers. The report often belongs to the producer or whoever ordered the test, and it may contain business details. It is therefore usually easier to ask the shop which points were tested and by which method than to ask for the paper itself.

Does a report apply forever

No. It applies to the batch that was tested, at that time. If the item is produced again, with another yarn or another dye, a new report is needed. An old report is therefore only a hint about a new item, not a guarantee that everything is as before.