Why does fabric shrink in the wash? Avoid nasty surprises

Many are surely familiar with the situation: a new garment, piece of fabric, or other textile goes into the washing machine after the first wash just the right size, but comes out a little smaller. Sometimes the change is barely noticeable, while other times it is several centimeters!

Fabric shrinkage is a completely normal phenomenon, but different materials behave in very different ways. However, with the right washing and a little foresight, shrinkage can often be reduced significantly.

Why does fabric shrink?

Fabric is made of fibers and yarns that have been subjected to stretching and tension during production. When the fabric then gets wet and heated in the wash, the fibers can return closer to their natural, original state. At the same time, the yarns and the weave can settle more tightly. As a result, the fabric becomes shorter or narrower.

Factors influencing shrinkage include, among others:

• the material of the fabric
• the weaving method
• tension created during production
• washing temperature
• intensity of the wash cycle
• spin speed
• drying method

Therefore, not all shrinkage is due to the fabric being of poor quality. Even good-quality natural fiber can shrink in the first wash.

Cotton can shrink in the first few washes

Cotton is one of the most common textile materials and also one of the materials for which shrinkage is easily noticed.

Tension is created in cotton fibers and the structure of the fabric during production. In the first wash, the fabric can relax and contract. Particularly, an excessively high washing temperature and a tumble dryer can increase shrinkage.

If a garment, bag, or home textile is being sewn from cotton fabric, it is usually worth washing the fabric before cutting. This way, any possible shrinkage happens before the work is finished.

Linen lives during use

Linen is a natural material whose properties include a certain liveliness. It may shrink somewhat during the first few washes and soften at the same time.

A linen fabric can feel quite firm and stiff when new, but diligent use and washing will gradually change its structure to be softer.

For linen, pre-washing is particularly useful when making a garment or other product whose dimensions should remain precise and unchanged.

It is advisable to treat linen according to the material's own washing instructions and to avoid unnecessarily high temperatures.

You can read more about linen and its properties in the article: Linen as a material in crafts

Wool shrinks differently

The shrinkage of wool differs from the shrinkage of cotton, for example.

The surface of a wool fiber has small scale-like structures. The combination of heat, moisture, and strong mechanical handling can cause the fibers to snag on each other. This is when wool begins to felt.

Therefore, a wool product can become not only smaller but also significantly denser if washed incorrectly.

When washing wool, you should avoid:

• high temperatures
• large temperature fluctuations
• strong spin cycles
• hard scrubbing.

For many wool products, airing them out—which is done less frequently than washing—is sufficient. So, don't wash wool garments unnecessarily. Wash them only when they are truly dirty.

More information on the properties and care of wool can be found in the Juuttisäkki article Wool as a material.

What about man-made fibers?

Polyester, polyamide, and many other synthetic fibers generally shrink less than natural fibers in a regular wash. However, they are not completely immutable either.

Too high a temperature can damage a man-made fiber or change the shape of the product. Specifically, the heat of a tumble dryer can be too high for some materials. The behavior of mixed fabrics also depends on what fibers they contain and in what proportions. For example, a cotton-polyester blend may shrink less than a 100% cotton fabric.

Why can a tumble dryer shrink textiles?

A tumble dryer combines heat and strong movement. Together, they can enhance the recovery of fibers and the fabric structure into a denser form. That is why a textile may shrink more in a tumble dryer than in a regular wash.

If the product's care label does not recommend tumble drying, it is advisable to follow the instruction and leave the tumble dryer unused. A more gentle alternative is often drying the textile in the open air at room temperature.

Should you wash the fabric before sewing?

In most cases, yes.

Especially with natural fiber fabrics, it is worth washing them before cutting and sewing in the same way the finished product will be washed later. If, for example, linen fabric is only washed for the first time after a precisely tailored garment has been sewn from it, the final result may be smaller than expected after the first wash.

When pre-washing, you should also consider the edges of the fabric. Some fabrics fray heavily in the wash, so the edges can be finished if necessary before washing. The fabric should also be straightened and ironed after washing before placing patterns and cutting.

Can a shrunken garment be restored to its original state?

Sometimes a textile can be carefully shaped while damp back toward its original dimensions. However, the properties of the fabric always suffer when it is stretched and shrunk unnecessarily.

The end result also depends largely on the material and what caused the shrinkage.

For example, a felted wool garment is difficult to restore to its original state because the fibers have already locked onto each other. Amusing pictures of small wool sweaters are fun, of course, but it is incredibly frustrating when your favorite sweater is unusable.

The best way is usually to prevent shrinkage in advance.

How to reduce textile shrinkage

With a few simple methods, you can extend the lifespan of your textiles and help them retain their original size and shape:

• Always check the product's washing instructions before washing.
• Do not use an unnecessarily high washing temperature.
• Choose a wash cycle suitable for the material.
• Avoid strong spin cycles for delicate materials.
• Use the tumble dryer only when allowed for the product.
• Wash natural fiber fabrics intended for sewing before cutting.
• If necessary, shape a delicate textile while damp to dry to its correct dimensions.

If the symbols on a garment or textile's care label feel unclear, the Taito.fi guide "Learn to read a garment's care label" clearly explains the most common washing, drying, and ironing symbols.

A little shrinkage is part of the nature of natural materials

Natural fibers are living materials. Cotton, linen, and wool react to moisture, heat, and use in different ways. A small change in a textile's dimensions does not necessarily mean there is something wrong with the product. It can be part of the material's natural behavior.

When you know the material's properties and follow the washing instructions, the textile will usually retain its shape, comfort, and beautiful appearance for much longer.

And if you are buying fabric for your own sewing project, one good rule of thumb is worth remembering: wash the fabric before you cut it. It can save a lot of frustration later.