  Traditionally, covariant scalar field theory models are either super
renormalizable, strictly renormalizable, or nonrenormalizable. The goal of
`Mixed Models' is to make sense of sums of these distinct examples, e.g.,
$g\varphi^4_3+g'\varphi^6_3+g''\varphi^8_3$, which includes an example of each
kind for spacetime dimension $n=3$. We show how the several interactions such
mixed models have may be turned on and off in any order without any
difficulties. Analogous results are shown for $g\varphi^4_n+g'\varphi^{138}_n$,
etc., for all $n\ge3$. Different categories hold for $n=2$ such as, e.g., ${g
P(\varphi)_2+g' N\!P}(\varphi)_2$, that involve polynomial ($P$) and suitable
nonpolynomial ($N\!P$) interactions, etc. Analogous situations for $n=1$ (time
alone) offer simple `toy' examples of how such mixed models may be constructed.
