In this review, we will be talking about the Su:m37 Bubble Mask Black. The way that this mask is formulated causes it to react with the oxygen in the air. This creates tiny bubbles, which in turn help the key ingredients of the mask to penetrate the skin. For those unfamiliar with the label, Su:m37 [pronounced soom-37] is a Korean skincare brand that’s famous in South Korea for its naturally-fermented range of skincare. It makes use of a natural fermentation process to extract the concentrated goodness of natural ingredients at 37°, as it is the optimal temperature for the fermentation process. And in case you are wondering, yes that explains the “37” in the brand name!