In this tutorial, I will show you how to make a procedural cardboard material using the shader nodes in Blender for your project.
Cardboard Base
Make sure you have the Node Wrangler add-on activated
Under the Shading Workspace, add a Voronoi Texture
Connect the Color output to the Base Color of the Principled Shader
Change the Scale to decrease the cell’s size
Select the Voronoi Texture and use CTRL + T to quickly add a Texture Coordinate and Mapping node
Change the Texture Coordinate node output to Object
Duplicate the Voronoi Texture node and increase the Scale
Connect the Vector of the Mapping node to the Vector of the second Voronoi Texture
Add a Mix Color node between the first Voronoi Texture and the Principled Shader
Connect the second Voronoi Texture to the Mix Color node
Add a Noise Texture node between the Texture Coordinate and Mapping nodes
Increase the Scale
Duplicate the Mix Color node and place it between the Noise Texture and Mapping nodes
Connect the Texture Coordinate node to the Mix Color node
Add a Color Ramp and connect it to the Roughness input of the Principled Shader
You can use the Color Stops to control the Roughness of the material
Cardboard Color
Add a Color Ramp between the first Mix Color node and the Principled Shader
Select the White Color Stop and change the color to a tan [#CCB5A4]
Select the Black Color Stop and change the color to a darker tan [#463D35]
Bump
Add a Bump node and connect the first Mix Color node to the Height of the Bump node
Connect the Bump node to the Normal of the Principled Shader and adjust the Strength
Displacement
If you want to use some displacement, switch to the Cycles Render Engine
Add a Displacement node and connect the Bump node to the Normal of the Displacement node
Connect the Displacement node to the Displacement of the Material Output
Add a Noise Texture between the Bump node and Displacement node