Why two identical pieces can measure differently

Short answer: Two pieces of the same style and size can measure one to two centimetres apart. This is because fabric stretches slightly differently when it lies ready for cutting. The difference is within the normal tolerance and is rarely felt on the body.

The fabric does not lie quite the same

A knit fabric is laid out in many layers on top of each other before it is cut. The layers give a little as they are laid out, and they never lie quite the same. A top layer can be slightly more stretched than a bottom one. When all layers are cut at once, each piece gets its own small deviations. See bamboo sweat for men and women.

Sewing adds small differences too

After cutting, the parts are sewn together. A seam can draw the fabric in slightly, and how much depends on how the fabric lies under the machine. These are small movements, but they add to the differences from cutting. The result is two pieces that look the same but do not measure quite the same.

The difference is within tolerance

One to two centimetres is the normal range in clothing production. It is called tolerance, and every maker works with it. As long as measurements are within that span, the piece is made as it should be. That is why the size guide shows the measurements the garment is drawn to, not a promise for every single piece. See most popular for women.

It is not a fault

A difference of one to two centimetres is not seen as a fault. It is a natural result of making clothes from a soft material in large numbers. Only when a measurement is clearly outside the tolerance is there a problem. If you are unsure about a piece, you can always contact customer service.

It is rarely felt on the body

On a fabric with stretch, the body evens out the difference by itself. A centimetre more or less in circumference disappears when the fabric rests against you and gives. That is why two identical pieces feel the same even if they measure a little differently on the table. You usually only notice if you measure.

When you own two of the same

If you have two of the same style, one may feel slightly longer or wider. Most often that is the tolerance you feel, not two different sizes. After a wash or two the difference often shrinks, as both pieces settle into their shape. See most popular from Copenhagen Bamboo.

Measure after washing

If you want to compare two pieces, wait until both have been washed. The first wash lets the fibres relax, which can change measurements slightly. Measure the pieces flat on a table without stretching them, and measure the same spot on both. That gives the clearest picture of whether they fit the same.

Use the guide as a guide

Because identical pieces can differ a little, the size guide should be read as a guide. If you are close to a boundary, fabric and fit decide which size suits you best. A fabric with stretch forgives a small deviation, while a firm fabric leaves less margin to work with.

Frequently asked questions

Why do two identical pieces measure differently

Because the fabric stretches slightly differently when the layers lie ready for cutting, and seams pull slightly differently. That gives deviations of one to two centimetres.

Is it a fault

No. One to two centimetres is within the normal tolerance in clothing production and is not seen as a fault, but as a result of a soft material.

Can you feel the difference

Rarely. On a fabric with stretch the body evens out a centimetre without you noticing, and after a wash the difference often gets smaller.