Academy / Sourcing Fundamentals

Size Does Matter.

Why textile sizing must be agreed before production.

8-minute read · For buyers sourcing apparel, uniforms, sportswear, workwear or promotional textiles

When buying textiles, sizing is one of the most common areas where things go wrong. A product can look good, feel good and be priced correctly — but if the sizing is wrong, it may not be suitable for the intended market.

Many factories work from their own standard size charts. These may be based on their domestic market, another export market, or a generic production template. That means a "Large" from one factory may not match a "Large" in the UK, Europe or the US. In some cases, an XL can feel more like a Medium, simply because the buyer assumed the size label meant the same thing.

This issue affects both small buyers and large organisations. It is not just a beginner mistake. Even experienced companies receive goods that are technically well made but commercially unusable because the fit is wrong.

The core problem

The risk is assuming that size labels are universal. They are not.

A factory may offer a T-shirt from Small Youth through to 5XL, but unless the buyer understands the measurements, grading and intended fit, there is no guarantee that the finished product will match the end customer's expectations.

Key risks

Different market sizing

Asian, European, UK and US sizing can vary significantly

Incorrect assumptions

Buyer orders "XL" expecting UK XL, but receives a much smaller fit

Poor grading

Smaller sizes may work, but larger sizes may not scale correctly

No fit approval

Product goes into bulk production before anyone has checked the real fit

Wrong garment type

Slim fit, regular fit, relaxed fit and oversized fit can all be interpreted differently

Label confusion

The label may say the right size, but the actual garment measurements may be wrong

Returns and complaints

Product may be rejected by the buyer or end user

Brand damage

Poor fit can make the product feel low quality, even if manufacturing is acceptable

Why factory size charts are not enough

A factory size guide is only useful if it is checked against the buyer's intended market. For example, a factory may produce a "standard adult XL", but that standard may be based on local retail sizing. If the buyer is selling or distributing in the UK, that XL may not match what a UK customer expects.

This becomes even more important when buying across a wide size range — Small Youth to 5XL, women's fitted, unisex, workwear, sportswear, promotional event clothing. The wider the size range, the more important the grading becomes. One sample size fitting correctly is not enough; the buyer needs confidence that each size has been scaled properly.

What buyers should do before ordering

01
Request the full size chart
Do not rely on size names alone — get every measurement
02
Check actual garment measurements
Chest, body length, sleeve length, shoulder width and tolerance
03
Confirm the target market
UK, EU, US or other regional fit expectations
04
Agree the fit style
Regular, slim, relaxed, oversized, women's fit, youth fit
05
Review grading between sizes
Make sure the jump between sizes is commercially sensible
06
Order fit samples
Test the actual garment before approving bulk production
07
Check larger sizes carefully
3XL, 4XL and 5XL often need more attention
08
Confirm measurement tolerances
Understand what variation is acceptable in production
09
Approve a final size specification
Lock this before production starts
10
Include size checks in QC
Sizing should be inspected during and after production

Fit samples are essential

A fit sample is not a formality. It is one of the most important approval stages in textile sourcing. Physically check the garment, compare it against the approved size chart and, where possible, test it on the intended wearer profile. This is especially important for uniforms, sportswear, staff clothing, event merchandise and retail apparel.

Skipping this stage to save time or cost creates much larger problems later. A £3 T-shirt is not good value if the finished product does not fit the people it was bought for.

The Viaty view

Sizing should be treated as a technical specification, not just a label. The correct approach is to define the size requirement before production, agree the measurements with the factory, approve samples and build size checks into the quality control process.

The question is not simply: "Can the factory make this T-shirt in XL?"

The better question is: "Can the factory make this T-shirt in an XL that fits our market, our customer and our intended use?"

That distinction is where many sourcing problems begin.

Lock sizing as a technical specification — not just a label

Viaty captures market, fit style, grading and tolerances on every textile brief. Fit samples are tracked. Final sign-off is logged.