Chern-Simons theory provides an attractive framework for quantizing 3d gravity without reference to holography. But how do we describe matter in CS gravity while retaining its useful features? In this talk, I will introduce a "Wilson spool," which provides an effective description of massive one-loop determinants directly as a gauge-invariant object. The spool can be heuristically viewed as a collection of Wilson loops winding in the Euclidean spacetime. I will illustrate it's utility for reproducing the one-loop determinants of massive scalar fields in both Anti-de Sitter and de Sitter backgrounds. In the context of de Sitter quantum gravity, exact results in Chern-Simons theory allow one to calculate the spool at finite G_N. This provides a method for investigating how dynamical gravity renormalizes the physics of massive matter.