An elastic map $\mathbf{T}$ associates stress with strain in some material. A symmetry of $\mathbf{T}$ is a rotation of the material that leaves $\mathbf{T}$ unchanged, and the symmetry group of $\mathbf{T}$ consists of all such rotations. The symmetry class of $\mathbf{T}$ describes the symmetry group but without the orientation information. With an eye toward geophysical applications, Browaeys & Chevrot developed a theory which, for any elastic map $\mathbf{T}$ and for each of six symmetry classes $\Sigma $ , computes the “ $\Sigma $ -percentage” of $\mathbf{T}$ . The theory also finds a “hexagonal approximation”—an approximation to $\mathbf{T}$ whose symmetry class is at least transverse isotropic. We reexamine their theory and recommend that the $\Sigma $ -percentages be abandoned. We also recommend that the hexagonal approximations to $\mathbf{T}$ be replaced with the closest transverse isotropic maps to $\mathbf{T}$ .