Write a fabric specification as a one-page table that lists each property of the cloth, the target value, the tolerance and the test method. Attach an approved sample and state that the sample is the standard wherever the table is silent. A tight brief produces a comparable quote from each mill and a clear basis for rejecting a bad lot.
Most purchasing managers inherit a spec from a previous supplier or copy one out of a garment tech pack. Both usually miss tolerances and test methods, the two things that decide a dispute. The list below covers the fields a woven cotton or blended fabric spec needs. Knitted fabric needs the same structure, with gauge and loop length in place of ends and picks.
Fields every fabric spec should carry
- Fibre content and tolerance, for example 100 percent cotton, or a stated blend with a tolerance of plus or minus 3 percent on each fibre.
- Yarn count in warp and weft, in the system the mill uses, with the fibre type where it matters, such as Shankar-6 cotton.
- Construction as ends per inch and picks per inch, with a tolerance, usually plus or minus 2 to 4 percent.
- Weave, such as plain, 2 by 1 twill, satin or dobby, with a swatch for anything non-standard.
- Weight in GSM with a tolerance, typically plus or minus 5 percent on finished fabric.
- Finished width in centimetres with a tolerance, usually plus or minus 1 to 2 centimetres, and whether the figure is cuttable or overall width.
- Finish, for example mercerised, peach, sanforised or enzyme washed, and any coating or resin.
- Colour reference and standard, such as a textile colour number or a physical lab dip, and the light source used for shade approval.
- Shade tolerance, usually stated as a Delta E limit or a grey scale grade against the approved standard.
- Shrinkage limit after washing, in warp and weft, typically a maximum of 3 percent for sanforised cotton.
- Colourfastness grades for washing, rubbing (dry and wet) and light, each stated as a minimum grade.
- Tear and tensile strength in warp and weft, with a minimum value.
- Pilling resistance as a minimum grade.
- Defect allowance under the four-point system, usually a maximum of 20 to 28 points per 100 square yards, plus the minimum first-piece length.
- Roll length, the number of pieces allowed per roll, and how joins are flagged.
- Packing, labelling and roll ticket content, including batch number, shade lot and metre count.
- Testing method references, ISO or AATCC as you prefer, named next to each test so the lab and the mill run the same procedure.
Tolerances and test methods decide disputes
A target value without a tolerance is an invitation to argue. State the range you will accept on every measured field, and state what happens outside it, for example a price adjustment for GSM between 5 and 8 percent short and rejection beyond that. Keep the tolerances realistic for the process. A mill cannot hold finished width to half a centimetre on a stenter and will either refuse the order or ignore the figure.
Name the test method beside each property. Shrinkage measured under one washing programme does not equal shrinkage measured under another, and colourfastness grades depend on the standard used. Choose ISO or AATCC according to what your own lab and your customers use, and write the number down so an NABL-accredited lab in India can run the same test.
The approved sample is the standard
Ask the mill for a pre-production sample, usually 3 to 5 metres, once the lab dip is approved. Test it, and if it passes, sign and seal two pieces, one kept by you and one by the mill. Write on the spec that the sealed sample governs hand feel, appearance and anything the table does not cover.
Issue the spec as a numbered, dated document and attach it to the purchase order. When you change a value, issue a new revision rather than an email.
How we help with specifications
We draft or tighten fabric specifications for buyers before any mill is approached, and we check that the mill's quality team has read and accepted each line. Pre-production samples are sealed on site and sent to an NABL-accredited lab under our control. If you have a spec you are not sure a mill can hold, we offer a free 20-minute sourcing review.