  We present an experimental investigation of drying suspensions of both hard
and soft nanolatex spheres. The crack formation is examined as a function of
the proportion of hard and soft deformable particles, leading to tunable
elastic properties of the drying film. In our experiments corresponding to a
given layer thickness, no crack formation could be observed below an onset
value of the proportion in hard spheres around 0.45. During the drying process,
the mass of films with various compositions in hard and soft spheres is
measured as a function of time. The results suggest that the soft particles
undergo deformation that releases the internal stresses. The spacing between
cracks is measured as a function of the layer thickness for various
compositions in hard and soft spheres.
