How to write a product specification sheet

A product specification sheet is the document that says, in measurable terms, what you are buying. Suppliers price from it, factories produce to it, inspectors check against it, and if something goes wrong, both sides return to it. A weak specification leaves each of those people to fill the gaps with their own assumptions.

This guide explains what to include and how to write requirements that can be checked.

What a specification sheet does

• Makes quotes comparable. Every supplier prices the same thing.
• Defines acceptance. It sets out what counts as conforming goods.
• Reduces disputes. "Good quality" cannot be measured; a stated value and method can.
• Preserves knowledge. Repeat orders and new staff start from the same reference.

A specification sheet is not a contract on its own. It should be referenced in the purchase order or sales contract so that it becomes part of the agreement.

Core sections

1. Identification

• Product name and a short description
• Your item code and the supplier's item code
• Document version number and date
• Intended use and target market

2. Materials and composition

State materials, grades and, where relevant, origin. For food and agricultural products, give variety, crop year and processing method. For manufactured goods, list main components and any restricted substances.

3. Dimensions and physical properties

Give each measurement with a unit and a tolerance. Include weight, colour (with a reference standard or physical swatch), finish and any other physical property that matters.

4. Performance and quality parameters

List each parameter with a target or limit, the unit and the test method. Examples include moisture content, strength, purity, burn time or electrical ratings, depending on the product.

5. Standards and compliance

Name the standards and regulations the product must meet in the destination market, with the edition where it matters. List the certificates and test reports the supplier must provide.

6. Packaging and labelling

• Unit, inner and outer packaging: material, dimensions, quantity per pack
• Net and gross weights
• Label content, language and placement
• Barcodes and carton marks
• Palletisation and container loading requirements

7. Inspection and acceptance

State how goods will be checked: sampling plan, defect classification, tests at inspection and who performs it. Refer to the approved sample by its identification.

8. Documents

List the documents required with each shipment, such as a certificate of analysis, certificate of origin or test report.

Write requirements that can be measured

The most useful habit is to give every requirement four parts: the parameter, the value, the tolerance and the method.

The values themselves must come from your own needs, your customer's requirements, the applicable standard or testing. Do not copy figures from another product or another market without checking them.

Other points of good practice:

• Use units consistently, and state them every time.
• Separate "must" from "preferred". Mark which requirements are mandatory.
• Write limits clearly: "maximum", "minimum" or a range, never just a number.
• State the basis where it matters, for example dry basis or as received.
• Avoid brand names as specifications unless only that brand is acceptable. If an equivalent is allowed, say who approves it.

Use photographs, drawings and samples

Words do not describe everything. Add:

• dimensioned drawings,
• photographs of acceptable and unacceptable appearance,
• colour references,
• an approved physical sample, signed and dated, with its reference number written in the specification.

Where the specification and the sample disagree, the contract should say which one prevails.

Version control

Specifications change. Manage the changes:

1. Give each version a number and date.
2. Record what changed and why.
3. Send the new version to the supplier and ask for written confirmation.
4. State the version number on each purchase order.

Many disputes come from a factory producing to an older version than the buyer had in mind.

Common mistakes

• Subjective wording, such as "premium", "high grade" or "export quality", with no definition.
• Missing tolerances. Nothing is produced to an exact number.
• No test method. Two laboratories can produce different results from the same sample.
• Leaving out packaging, although it causes a large share of transit damage and import problems.
• Over-specifying. Tighter limits than you need raise the price and shrink the pool of suppliers.
• Ignoring destination rules. Labelling and compliance requirements belong in the specification.
• Not referencing it in the order. A specification that is not part of the contract is only a wish list.

If you do not have all the answers

Few buyers can fill in every field on the first attempt. Start with what you know: the use, the market, the quantity and any reference product. Ask suppliers for their standard data sheet and use it as a draft, then adjust it to your needs. Test samples to find out which values you can accept.

This article is general guidance. For regulated products, confirm requirements with the competent authority or a qualified adviser.

Next steps

A specification sheet pairs naturally with a clear enquiry. See what to include in a quote request, and for private label projects, from sample to shipment.

When your draft is ready, request a quote and attach it. If you only have a partial specification, send that with your end use and we will help identify what is missing.