Still working through my abundance of samples (all invariably good), but this was an unexpected gem, second only to the oxygen silk - which is hands down. I've been adverse to acid serums in the past finding most to have a residual stickiness that never quite goes away, then drying down to form a fine shiny film. Not the case here. I get complete absorption instantly, even layering twice or combined with other serums, always resulting in extremely smooth, soft skin that is unbudgeably matte. Planning to go full size when I'm tapped out, but the sample was so generous I had to transfer it to a small jar. An excellent and versatile exfoliating treatment.