Curtains shrank after washing - why and what to do

What to do now

1. Do not wash it hot again Repeated hot washing or a tumble dryer does not reduce the shrinkage and can increase it; UW-Extension describes this for wool.
2. Measure and compare Measure the width and length of the shrunk curtain and compare it with the other curtain of the same pair or with the size you bought.
3. Read the labels In a lined curtain the face fabric and the lining may be made of different fibres. Look at both labels, if there are any.
4. Check the hem If the edge has become wavy or the bottom has pulled in, write that down when you ask for help. Cleaning does not straighten it.
5. Wash the others differently If the pair has a curtain you have not washed yet, do not wash it the same way until it is clear why the first one shrank.

Why curtains shrink

NC State Extension’s guide to textiles after flooding says that when curtains and other fabrics get soaked, they often change colour, the dye bleeds, they shrink and water marks remain. The fabric maker Brentano writes that natural fibres react to humidity in the air and the length of a curtain can change by up to 3%.

Viscose is much weaker wet than dry and can change shape: stretch or shrink (Ohio State University fact sheet HYG-5538). In wool, hot water together with rubbing or the movement of a washing machine felts the fibres, and the fabric shrinks and becomes denser (University of Wisconsin Extension material on felting). This kind of shrinkage usually cannot be reversed.

How to wash curtains in a washing machine so they do not shrink

The care label matters most. Care symbols are described by the GINETEX system and the ISO 3758 standard: a crossed-out symbol means “do not”, the tub symbol refers to washing in water, a circle with a letter means professional cleaning, and bars under a symbol mean a gentler process. If the tub is crossed out, do not wash the curtain in a washing machine.

• Do not wash hotter than the label says.
• Follow the bars under the symbol: they mean a gentler programme.
• Do not tumble-dry blackout curtains and do not iron the coated side with a hot iron: makers warn that heat can make the coating crack.
• Do not pull or wring a wet viscose curtain: it is weak when wet.
• Test a new product on a hidden spot first.

Before washing, measure the curtain and write down the length. Then afterwards you can see at once whether and by how much it has changed. If the length of a natural-fibre curtain changes slightly with the humidity in the air, that is a property of the fibre, not damage.

What not to do with a shrunk curtain

Do not try to stretch a wet curtain by force or hang weights on it. Viscose is weak when wet and can change shape, so the fabric may end up uneven and wavy. A hot iron used to “stretch” the fabric is also a risk for blackout and synthetic fabrics.

If the curtain has become too short, that is a sewing question: the hem can be let out or lengthened with a strip of fabric. Cleaning does not bring the length back.

When to have curtains professionally cleaned

• the label says professional cleaning or forbids washing in water;
• velvet, silk, wool or viscose;
• lined and double curtains with different labels;
• blackout curtains with a coating;
• large, heavy curtains that do not fit in a washing machine.

The cleaning price is per square metre of fabric: thin and day curtains, sheers from €2.30/m², heavy, night and double curtains from €3.70/m². Example: two heavy curtains, each 1.5 × 2.6 m of fabric: 7.8 m² × €3.70 = €28.86, so the charge is €45 (the minimum order). For such fabrics, see curtain dry cleaning.