A dynamic mechanical. thermal analysis (DMTA) performed on stacked coated supports or on samples sandwiched between rigid supports (carbon or glass fibers, metal or glass plates, ...)is described. The choice of a dual cantilever deformation favors the shear strain of the less stiff material between the more rigid supports. A theoretical model demonstrates that the less stiff material response is mainly recorded and moreover amplified. An exceptional sensitivity to the soft material is therefore observed. This method does not require any special sample (only stacking of coated supports or sample sandwiching) whilst it enables to characterize in situ polymer coating, even nanocoating. This characterization is of prime interest in technological coating developments such as paints, fiber sizings, glues, ... This possible measurement of thermal transitions peculiar to nanocoatings also opens more fundamental studies as the probing of interface influence on thermal transitions. (C) 2001 Elsevier Science Ltd. All rights reserved.