All of the following are types of "proper" connective tissue, except:

Proper connective tissue includes a variety of tissue types that provide structural and functional support within the body. Areolar, adipose, and reticular tissues are all recognized categories of proper connective tissue.

Areolar tissue is a loose connective tissue that cushions organs and provides flexibility while allowing for movement. Adipose tissue, or fat tissue, stores energy and provides insulation and cushioning for the body. Reticular tissue is a type of connective tissue that forms a supportive framework for organs, typically found in lymph nodes, the spleen, and bone marrow.

In contrast, aspartic is not a type of connective tissue; rather, it is an amino acid that plays a role in various metabolic processes and protein synthesis. It does not fit within the classification of "proper" connective tissues, as proper connective tissue is defined by its structural and supportive roles in the body rather than being a biochemical compound or building block like aspartic.