Aspic-based terrines are simply glorified gelatin molds—that is, they consist of solid ingredients held together by gelatin in the form of aspic jelly.
The proportion of aspic to solids can vary greatly. At one extreme, there may be just enough aspic to hold the solid ingredients together, so the aspic jelly itself is almost not evident. On the other hand, the aspic may predominate, with solid ingredients suspended in it at intervals. For this latter type to succeed, the aspic jelly must be of excellent quality, with good flavor, a firm but not rubbery texture, and sparkling clarity.