Very similar Henri.. A foam core, with a thin plastic sheet either side.. Commonly used for short-life advertising signs. - Name and party of local candidate at elections, 'for sale' signs,that type of thing.
It is very often not UV stable, but a coat of paint protects it.
It comes in various thicknesses.
You can use the edge of an old screwdriver (flat blade) to 'score' indentations in it to create a brick pattern.