Would you rather run into a brick wall or into a mattress? For most people, the choice is not difficult. A brick wall is stiff and does not absorb shocks or vibrations well; a mattress is soft and is a good shock absorber. Sometimes, in designing materials, both of these properties are needed. Materials should be good at absorbing vibrations, but should be stiff enough to not collapse under pressure. A team of researchers from the UvA Institute of Physics has now found a way to design materials that manage to do both these things.