  The determination of the contact area is a key step to derive mechanical
properties such as hardness or an elastic modulus by instrumented indentation
testing. Two families of procedures are dedicated to extracting this area: on
the one hand, post mortem measurements that require residual imprint imaging,
and on the other hand, direct methods that only rely on the load vs. the
penetration depth curve. With the development of built-in scanning probe
microscopy imaging capabilities such as atomic force microscopy and indentation
tip scanning probe microscopy, last generation indentation devices have made
systematic residual imprint imaging much faster and more reliable. In this
paper, a new post mortem method is introduced and further compared to three
existing classical direct methods by means of a numerical and experimental
benchmark covering a large range of materials. It is shown that the new method
systematically leads to lower error levels regardless of the type of material.
Pros and cons of the new method vs. direct methods are also discussed,
demonstrating its efficiency in easily extracting mechanical properties with an
enhanced confidence.
