  We investigate the dependence of the stickiness parameters $t_{ij}=1/(12\tau
_{ij})$ -- where the $\tau_{ij}$ are the conventional Baxter parameters -- on
the solute diameters $\sigma_{i}$ and $\sigma_{j}$ in multicomponent sticky
hard sphere (SHS) models for fluid mixtures of mesoscopic neutral particles. A
variety of simple but realistic interaction potentials, utilized in the
literature to model \textit{short-ranged attractions} present in real solutions
of colloids or reverse micelles, is reviewed. We consider: i) van der Waals
attractions, ii) hard-sphere-depletion forces, iii) polymer-coated colloids,
iv) solvation effects (in particular hydrophobic bonding and attractions
between reverse micelles of water-in-oil microemulsions). We map each of these
potentials onto an equivalent SHS model, by requiring the equality of the
second virial coefficients. The main finding is that, for most of the
potentials considered, the size-dependence of $t_{ij}(T,\sigma_{i},\sigma
_{j})$ can be approximated by essentially the same expression, i.e. a simple
polynomial in the variable $\sigma_{i}\sigma_{j}/\sigma_{ij}^{2}$, with
coefficients depending on the temperature $T$, or -- for depletion interactions
-- on the packing fraction $\eta_{0}$ of the depletant particles.
