A polar fleece sample may have the right softness and appearance, but this does not guarantee that the bulk fabric will have the same weight, width, pile surface or color.
Before production, the approved sample should be converted into a clear fabric specification. For most polar fleece orders, the main points are:
- Finished GSM
- Finished and usable width
- Brushing construction
- Pile appearance
- Anti-pilling requirement
- Approved color and bulk shade tolerance
These points should be confirmed before bulk knitting, dyeing and finishing begin.
Define What the Approved Sample Controls
An approved sample should not be treated as a general reference without explaining what has been approved.
For example, a lab dip normally confirms color, but it does not automatically approve GSM, pile height or hand feel. A small quality sample may confirm the surface construction, but it may not represent the exact bulk color.
The approval record should identify whether the sample controls:
| Approval Item | What the Sample Should Confirm |
|---|---|
| Fabric quality | Composition, construction and finished GSM |
| Surface | Brushed side, pile height, density and shearing |
| Hand feel | Softness, fullness and surface touch |
| Color | Approved lab dip or production shade |
| Complete quality | All agreed fabric specifications |
For a complete quality approval, the fabric face and reverse should be marked clearly, especially when the two sides receive different brushing or anti-pilling finishes.
Confirm Finished GSM and Usable Width
Finished GSM
The specified GSM should refer to the fabric after dyeing, brushing, shearing, anti-pilling finishing and final setting.
Do not use a broad description such as:
200–300 GSM polar fleece
This range covers several distinctly different fabric qualities.
A clearer specification is:
Target finished GSM: 250 GSM
Bulk tolerance: ±5% or as agreed
The permitted tolerance should be agreed for the actual order rather than treated as a universal value.
ASTM D3776/D3776M covers the measurement of fabric mass per unit area. The supplier and sourcing team do not necessarily need to include the full standard in the purchase order, but they should use the same measurement basis when comparing the approved sample and bulk fabric.
The main point is to avoid approving a 250 GSM sample and later accepting bulk rolls that feel noticeably lighter simply because the shipment average remains close to the target.
Finished Width and Usable Width
Finished width and usable width should be written separately.
- Finished width is the complete width of the fabric.
- Usable width excludes curled, distorted or unstable edge areas that cannot be used reliably during cutting.
ASTM D3774 specifically covers fabric width, usable width or both, which supports treating them as separate specifications.
A practical specification may be written as:
Finished width: 160 cm
Minimum usable width: 156 cm
This is more useful than writing only “160 cm width.” A roll may reach the required total width but still provide less usable fabric because of edge curling or irregular finishing.
Specify the Brushing Construction Precisely
“Double-sided fleece” is not a sufficiently precise description.
The specification should identify:
- Which side is brushed
- Which side receives anti-pilling finishing
- Which surface is used as the fabric face
- Whether both sides should have a similar appearance
The three common constructions should be distinguished clearly.
Single Brushed, Single Anti-Pilling
One side is brushed and finished for improved pilling resistance. The reverse retains a flatter knitted surface.
This construction is suitable when only one side needs to provide the main fleece appearance.
Double Brushed, Single Anti-Pilling
Both sides are brushed, but only the designated face receives the required anti-pilling finish.
The face and reverse may therefore have different pile appearance and performance.
Double Brushed, Double Anti-Pilling
Both sides are brushed and both sides receive anti-pilling finishing.
This should still not be interpreted as meaning that the two surfaces must look identical. Their required appearance should be confirmed against the approved sample.
During pre-production approval, compare these five surface details:
- Pile height
The bulk pile should not be visibly shorter or longer than the approved sample. - Pile density
The knitted base should not become clearly visible when the surface is viewed normally. - Brushing uniformity
The surface should not contain obvious thin, flat or over-brushed areas. - Shearing consistency
Uneven shearing can create stripes or irregular light reflection across the fabric. - Face-to-reverse difference
For double-brushed qualities, the expected difference between the two sides should be defined before production.
These details are more useful than using “soft hand feel” as the main approval standard. Softness alone cannot confirm pile density, shearing quality or surface uniformity.
Write a Complete Anti-Pilling Requirement
An anti-pilling grade should not be written without specifying which surface and fabric condition it applies to.
ISO 12945-2 covers the modified Martindale method for evaluating fabric pilling, fuzzing and matting. The article does not need to explain the complete procedure, but the order should identify the agreed method so that the sample and bulk fabric are evaluated on the same basis.
Instead of writing:
Anti-pilling grade 4
Use a complete specification such as:
Anti-pilling: Grade 4 minimum on the fabric face, tested on the final finished fabric using the agreed method and test cycle.
For double-brushed fabric, specify whether the requirement applies to:
- The face only
- The reverse only
- Both sides
The test sample should be taken after the final brushing, shearing and finishing process. A result obtained before final finishing does not represent the actual bulk surface.
Control Color by Pile Direction and Dye Lot
The approved lab dip should be the main color reference, but polar fleece requires an additional visual check because pile direction changes how light is reflected from the surface.
When comparing the lab dip, pre-production sample and bulk cuttings:
- Place all samples in the same pile direction.
- Compare the same fabric side.
- Use the same lighting conditions.
- Check different dye lots separately.
ISO 105-J03 describes the calculation of color difference between specimens of the same material measured under the same conditions. This supports the need to keep the material surface, direction and comparison conditions consistent.
A sample viewed with the pile running upward may appear darker than the same fabric viewed in the opposite direction. This visual difference should not be confused with an actual dyeing difference.
Before bulk production, also confirm whether:
- All rolls must come from one dye lot
- Multiple dye lots may be supplied separately
- A light-to-dark bulk shade range is acceptable
- Different dye lots may be used in the same cutting program
For color-sensitive orders, an approved bulk shade band is more practical than relying on one lab dip alone.
Use One Pre-Bulk Specification Table
The final approval can be summarized in one table rather than several separate checklists.
| Specification | Example of a Clear Requirement |
|---|---|
| Composition | 100% polyester |
| Finished GSM | 250 GSM, agreed bulk tolerance |
| Finished width | 160 cm |
| Usable width | Minimum 156 cm |
| Brushing | Double brushed |
| Anti-pilling | Single-side anti-pilling on the designated face |
| Pile surface | Match approved sample for height, density and shearing |
| Anti-pilling grade | Minimum agreed grade, method and tested side specified |
| Color | Match approved lab dip |
| Bulk shade | Within approved shade range |
| Fabric face | Clearly marked on the approved reference |
Conclusion
Polar fleece quality should be controlled by a small number of clearly written specifications rather than a long list of general quality requirements.
Before bulk production, confirm the finished GSM, usable width, brushing structure, pile appearance, anti-pilling requirement and acceptable color range. These details provide a more reliable bulk production target than approving the fabric by softness or appearance alone.