Microfiber applicators make coating product application easier, quicker and more efficient, but coatings typically have a lower viscosity (not as thick - flow easier) so they soak through the microfiber to the sponge, wasting valuable product.
 
The solution to this problem is that these mini microfiber applicator detailing sponges have an added layer of a hydrophobic material between the microfiber and sponge. This prevents excess coating product from soaking through the microfiber into the sponge. It also limits excess product buildup which can become gummy and tacky as the coating begins to cure.