What type of surface allows for some liquid penetration but not entirely?

The type of surface that allows for some liquid penetration but not entirely is best described as semi-porous. Semi-porous materials have a limited number of pores that can absorb liquids, but not to the same extent as fully porous materials. This means that while they can permit some liquid to seep in, they also retain a significant portion of liquid on the surface, preventing complete saturation.

In contrast, non-porous surfaces do not allow any penetration of liquids, as they are solid and impervious. Porous surfaces allow for full liquid penetration through numerous pores, leading to complete absorption. Opaque refers to materials that do not permit light to pass through, which does not relate to the penetration of liquids. Thus, semi-porous accurately describes a surface that permits limited absorption while retaining resistance to total penetration.