It is worth noting that, once formed in the tapered channels, clogs are not later disrupted, even at high ∆P. This can be seen in microscopy videos of clog growth obtained during a typical flow test (see Videos S4 and S5 in SI). Neither gradual nor abrupt increases in ∆P can dislodge clogs, not even when the pressure is suddenly increased from 500 to 2000 mbar (see Videos S8 and S9 in SI). Not even flow reversal dislodges the clogs (see Video S10 in SI). In all cases, clogs grow discontinuously, and remain stable for the duration of the flow tests. Therefore, the concept of clog prevention at high ∆P suggests there is a moment in which particles may or may not form a bridge. Indeed, recent experiments and simulations reveal transient clogging of colloids navigating an abrupt constriction; these clogs can have infinitesimal lifetimes . But, once formed, these clogs are remarkably stable. Interestingly, this observation contrasts those in which perturbation can be used to dislodge a clog, as in hopper flows or silo discharge .