Systems and methods are involved with but are not limited to: a first case portion including a first interior portion, the first interior portion including a first layer and a plurality of first protrusions, the plurality of first protrusions coupled to the first layer and extending therefrom, the plurality of first protrusions configured to affixedly engage with one or more smooth surface portions of a rear side portion of a portable device keyboard assembly. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present disclosure.