# 2.2.7: Specify Materials

Materials can be either defined by manually setting their mechanic properties or by selection from a library of predefined materials (see fig. 2.2.7.1 (3)). Materials attach to cross sections. There are two options for assigning materials:

![Fig. 2.2.7.1: Definition of materials via element names](/files/-M9XuRnKh8vcpJxtHXhv)

1. Assignment via the **“Assemble”**-component (see fig. 2.2.7.1). The **“Elem|Id”** input-plug specifies the names of the elements to which the material shall be attached. Alternatively a regular expression can be used to select elements. Leaving **“Elem|Id”** empty sets the material for all elements. Materials are not attached to elements directly but to the element’s cross section. 
2. Direct input at the **“Cross Section”**-component like in fig. 2.2.7.2.

![ Fig. 2.2.7.2: Definition of a material directly at the "Element"-component](/files/-M9XuRnLZULqINGpBAMS)

Fig. 2.2.7.1 shows how materials can be defined by element names **“Elem|Id”**: definition of an isotropic custom material (1); definition of an orthotropic custom material (2); selection of a material from the material library (3).

{% hint style="info" %}
Assignment via the **“Assemble”**-component overrides direct assignment in the cross section.
{% endhint %}

{% hint style="info" %}
Should you not assign a material to your beam or shell elements, the [default material ](/2-getting-started/2-getting-started-1/karamba3d-entities.md#default-settings)will be used.
{% endhint %}


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