Sarcolemma of skeletal muscle prepared by a quick-freeze deep-etch method also shows the basement membrane (lamina externa, labeled here as the basal lamina) associated with the muscle fiber. This method reveals a basement membrane composed of a meshwork of fibers, some of which contact the cell membrane. The larger fibrils outside of the lamina externa (to the far lower right of the image) are composed of collagen. Image by John Heuser, Figure 29 from Chapter 1 (The Cell Surface) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.