Measured UV extinction behavior for molecular‐beam extracted amorphous carbon grains embedded in argon ice (ACI sample; solid line) and collected on substrate (ACC sample; dashed line) in comparison with the published results for benzene flame soot (Colangeli et al. 1995, called BE sample therein; dash‐dotted line) and a HAC sample annealed for 3 hr at 800°C (Mennella et al. 1995, called AC800 sample therein; dotted line). The ripple structure superimposed on the solid line is an interference effect caused by multiple reflection in the thin ice layer.