Additionally, the stability of the three suspensions was evaluated by depositing the flakes on Si/SiO 2 substrates at different days since the suspensions of exfoliated matrials were prepared. In Fig. ) we see that after 5 days, there are no flakes in the MnPS 3 @H 2 O sample. In contrast, the samples covered by a polymer are stable for days (or even weeks, ESI Fig. ). Thus, after 35 days, we have been capable of measuring flakes with the same size and shape as the first day, suggesting that the tight polymeric layer keeps the flakes isolated in solution and prevents further restacking. Therefore, if we want to preserve a stable ink of MnPS 3 flakes, the presence of a capping agent is mandatory. In contrast, if bare flakes are requested for a specific application, it is desirable to use freshly prepared suspensions.