A cold weather programme usually fails in the document rather than in the factory. The garments that arrive are the garments that were described, and if the description did not say how the layers work together, how the sizing allows for the stack, or what happens when the wearer stops moving, the supplier cannot be blamed. This guide sets out a structure that can be quoted against, inspected and repeated.
Start with the conditions, not the product
Write down what the wearer will actually face before naming a single garment: the climate through the working year, the dominant weather condition, whether the wearer moves or waits, how long they are exposed without shelter, and what equipment they carry. Two programmes that both say cold weather can have almost nothing else in common, and almost every dispute about the same garment traces back to one of those facts being different between buyer and supplier.
We deliberately do not ask for a temperature figure to design against, and buyers should be careful about any specification built on one. How a system feels depends on activity, wind, humidity, exposure time, layer configuration and individual variation, and none of those are captured by a single number. Describe the conditions, and let the composition follow.
The eight sections of a cold weather specification
| Section | What it fixes | Why it is in the document |
|---|---|---|
| Conditions | Climate, weather, activity, exposure, equipment | Decides every other section |
| System | Layer count, order, which layers are removable | Prevents four good garments that do not work together |
| Materials | Fabric, insulation and trim specification per layer and position | Makes substitution visible |
| Construction | Seams, closures, storm flaps, ventilation, reinforcement, hood and cuff interfaces | Where performance is actually won or lost |
| Sizing | Graded chart, layer allowance, tolerances | The most common cause of rejection after delivery |
| Labelling and issue | Labels, care labels, size identification, packing | Decides whether the system can be managed in service |
| Evidence | Test methods, sample approval, inspection standard | Makes claims checkable |
| Repeatability | Retained sample, material standard, documentation held with the order | Decides whether order two matches order one |
Eight headings are enough. A specification is not improved by length; it is improved by being unambiguous about the decisions a supplier has to make.
Specify the system before the garments
The single most useful change a buyer can make is to write the layer composition first. State how many layers are worn together, in what order, which of them are removed during exertion, which are issued as a set and which are replaceable on their own. Then define each garment as a component of that composition.
This is also the cheapest place to fix problems. Interfaces — a cuff against a glove, a hem against a boot, a hood against headwear — cost nothing to change on paper and a great deal after sampling. The same is true of load-bearing equipment, where a waist that shifts or a pocket that cannot be reached with equipment on is a specification failure rather than a manufacturing defect.
Sizing and layer allowance
Sizing has to be developed with the layer stack in mind, because the body dimensions the garment covers are not the body dimensions the size chart describes. Chest, shoulder width, back length and sleeve length all need to allow for the layers beneath, and sleeve length is especially sensitive because the layers shorten effective reach. State the layer allowance explicitly, and state it as a requirement rather than letting each supplier interpret it.
Sizing also has to be confirmed rather than assumed. A graded size set produced against the intended composition, measured and checked on wearers in the full stack, is what turns a size chart into a specification. Our cold weather mobility page describes how restriction under a full stack is assessed, and our size development process is where the chart is built.
Materials and where substitution is allowed
List materials by layer and position, not as a single fabric line. A cold weather system uses different materials for the base layer, the mid layer, the insulation and the shell, and they are chosen for different jobs: moisture wicking fabric at the skin, cold weather insulation material in the middle, and waterproof fabric or a wind-resistant outer where the weather demands it. Name the shell requirement precisely, because water resistance and waterproof construction are different specifications with different costs.
Then state where substitution is permitted and who approves it. Most disputes about material substitution would disappear if the document said that the material is fixed, and any change requires written approval and a re-submitted sample before production.
Test methods, evidence and documentation
Where you need measured performance, agree the test method first and require the result to be produced on the actual construction rather than on a material sample. Ask for the report to identify the method, the conditioning, the specimen and the issuing laboratory, and decide in advance whether the testing must be independent. A method agreed after the garments are made describes what you received rather than setting a requirement.
For construction questions that no laboratory answers — how a cuff seals over a glove, whether a vent is usable with equipment on — the specification should require a trial. Our cold chamber test page describes how we intend to assess a full composition in controlled conditions and what a chamber cannot reproduce. None of this replaces the buyer's own field trials: any comfort conclusion for a programme has to come from testing the actual composition on the actual wearers in the actual conditions, and that is the evidence worth holding a supplier to.
Approval, inspection and the second order
Finish with the mechanics of control: the pre-production sample and what it is approved against, the AQL level and the measurement points checked at final inspection, and how the approved sample and material standard are retained for the next order. A repeat order that arrives different usually means one of those three steps was skipped.
If you are building the document from scratch, our guide to writing a tactical apparel tech pack covers the garment-level detail, and what a fabric test report tells you covers how to read what comes back. The composition itself, including how layers, sizes and shells are agreed, is set out in our extreme cold weather programme, and cold weather uniform sets shows how a complete issue is documented.
FAQ
Do I need a temperature figure to write a cold weather specification?
No, and specifying one is risky. How a system feels depends on activity, wind, humidity, exposure time, layers worn and individual variation, so a single temperature figure does not describe what the wearer experiences. Describe the conditions the programme faces and require the composition to be verified by trial instead.
How long should the specification be?
Long enough to remove every decision a supplier might otherwise make for you, and no longer. Most programmes are covered by eight sections covering conditions, system, materials, construction, sizing, labelling, evidence and repeatability. Appendices can carry fabrics, measurements and inspection detail.
Should the specification cover one garment or the whole system?
The whole system, even if you order one garment at a time. Layer count, interfaces and sizing allowance are system decisions, and a garment specified in isolation is how a programme ends up with pieces that do not work together.
How do I handle suppliers who propose substitutions?
Say in the document that the material is fixed and that any substitution requires written approval and a re-submitted sample before production. Then compare quotations line by line against the document, because an unexplained price difference is usually the substitution you did not approve.
What happens if we need to change the specification after sampling?
Change it deliberately and document the change, then re-approve the sample. A specification that changes during production cannot be inspected, and it also cannot be repeated, which means the next order becomes a negotiation about what was meant rather than a copy of what was approved.