The concept of the test painting involves a reproducible preparation method: material coating, composition and thicknesses are as close as possible.  The second central aspect is considerably more complex:  how to simulate the fragility of real paintings? This was done by restorers from the research team developing a concept integrating selected criteria (e.g. loss of adhesion between paint layer and support), which make paintings more fragile and can be reproduced with test paintings.  The representativeness of the test paintings is thus not transferable to individual real paintings but to paintings that display classic signs of fragility.