Comparison between experiment (a–f) and simulation (g–n) of the laser-driven spatter process in powder, showing good qualitative agreement. The experiment consists of experimental snapshots showing droplet formation and ejection. The illumination laser (Cavilux with filter in a–c; Thorlabs, no filter in d–f) is on and the powder can be observed in the background. (a–c) illustrates a small 10 μm droplet forming and ejecting away from the melt similar to a bare plate. The melt pool is highlighted with blue dashed lines. The spatter forms as a protuberance in (a), elongated neck thins out in (b) and escapes as a spherical droplet in (c) (circled in red). (d–f) illustrates a larger droplet forming from liquid buildup at the front of the melt due to the presence of powder (circled in red). The melt collects in front of the depression in (d) and is plowed forward in (e) while collecting mass and escapes the melt pool in (f) to land a short distance. The simulation (g–j) shows four snapshots representing the droplet ejection in (d–f). Snapshots (k–n) shows a sub-threshold ejection event. The droplet is flattened on the left side in (k), is entrained by the rotation flow towards the back and subsumed by the melt pool (l–n). Experimental parameters Ti6-4, P = 300 W and u = 1. 5 m/s for (a–c) and SS316L, P = 200 W, u = 2.0 m/s for (d–f) and simulation parameters SS316L, P = 200 W, u = 1.5 m/s.