Let t be a positive integer, and let K = (k 1 , . . . , k t ) and L = (l 1 , . . . , l t ) be collections of nonnegative integers. A (t, K, L)-factorization of a graph is a decomposition of the graph into factors F 1 , . . . , F t such that F i is k i -regular and l i -edge-connected. In this paper, we apply the technique of amalgamations of graphs to study (t, K, L)-factorizations of complete graphs. In particular, we describe precisely when it is possible to embed a factorization of K m in a (t, K, L)-factorization of K n .