A holder for knives or tools includes a vessel of an elastic material that has a chamber. Linear bristles fill and are arranged in adjacent rows within the chamber so that the vessel exerts a compression force on the linear bristles. Each bristle has a generally rectangular cross-section transverse to a length of the bristle. The linear bristles receive and retain knives or tools via a friction force irrespective of the orientation of the knives or tools when inserted into the vessel and irrespective of the orientation of the vessel. The holder assembly can include a suction cup via which the vessel can be coupled to a surface, and a base plate that receives the suction cup for mounting to different (e.g., uneven, non-smooth) surfaces.