The AFM images were taken using NanoWizard 3 instrument (JPK, Berlin, Germany) at AC mode. The silicon tip used had a spring constant of 6 N/m (Aspire, Team Nanotec GmbH, Villingen-Schwenningen, Germany). The sample of coacervates formed in solution was prepared with pep1 (10 mM) in carbonate buffer (pH 10.5, 25 mM, 3 M NaCl). For the coacervates formed during evaporation, a sample of pep1 (10 mM) in acetate buffer (pH 4.8, 25 mM, 0.3 M NaCl) was prepared. In both cases, the solutions were deposited on glass slides and allowed to evaporate before the imaging.