Specimens for evaluating corrosion protection of substrates due, at least in part, to coatings applied thereupon are described. A specimen (1) comprises: a first coating (10), comprising a first set of layers (11) including a first layer (11A), on a first substrate (12); and a first set of perforations (100), including a first perforation (100A) and a second perforation (100B), in the first coating (10), wherein the first perforation (100A) has a first depth D1 through the first coating (10) and a first dimension W1 transverse to the first depth, wherein the second perforation (100B) has a second depth D2 through the first coating (10) and a second dimension transverse to the second depth D2 and wherein the first dimension W1 and the second dimension W2 are different.