Curtain fabrics and their translucency

If you want to buy curtains, you often think about the darkening effect, the opacity and the thermal protection of the curtains. How it relates to the translucency of curtains in general, and what the specified values ​​mean, you can read here.

Properties of substances

Each fabric has certain properties in terms of light transmission and heat reflection. You can not see this from the outside immediately, especially with curtains.

Therefore, there are fixed physical values ​​to which one can orient. In many cases, only individual values ​​are given by the manufacturer, or only general statements are made. Detailed information is more common with pleats.

The common values ​​that should be considered are:

  • Transmittance of the tissue
  • Reflectance of the tissue
  • Degree of transparency of the fabric
  • Absorbance of the tissue

Transmittance of the tissue

The transmittance of the tissue indicates how much of the incident light is transmitted by the tissue. For darkening curtains, this value should be 0%. When the curtains are closed then no more light falls through. This is important for bedrooms, for example, if you want to sleep in the dark.

However, if it is only about light or privacy, and no complete obscuration is sought, other values ​​are relevant.

Degree of transparency of the fabric

Transparency is usually specified only in certain classes. Substances can have the following properties:

  • transparent
  • semi-transparent
  • translucent as well
  • dim out and darken

Very low degrees of transparency thus mean at the same time very low transmittances. High transparency means there is virtually no proper privacy.

Semitransparent fabrics usually allow almost all daylight, while at the same time there is some privacy. Translucent fabrics allow much of the daylight through, but offer a total opacity.

Reflectance of the tissue

Fabrics can be coated differently. A highly reflective coating causes a large part of the incident sun rays and especially the heat radiation is reflected from the outside. This is an advantage in the summer, when a heating of the rooms should be avoided as effectively as possible.

Fabrics can be different reflective. Many roller blinds and pleats are additionally specially coated to obtain a particularly high degree of reflection. For curtain fabrics that is less common for cost reasons.

Absorbance of the tissue

Absorption means ingestion. It is about the ability of the substance to swallow and store incident light and heat radiation instead of letting it through. Many curtains, especially thermogardins, have a particularly high degree of absorption due to their type of fabric and their layer structure.

The connection between absorption, reflection and transmission is quite simple:

Absorptance + reflectance + transmittance = 100%

The distribution on the individual points then indicates in total what the substance can do.

material properties

For the degree of transmittance and the degree of absorption in curtains, the material density (darkening above about 320 g / m²) and the weave of the fabric play an important role. For multi-layer curtains, which consist of different layers sewn together, the properties of each individual layer are decisive, and then they add up.

Video Board: How to fold and store your fabric