  The aim of this article is to study the behaviour of the multifractal packing
function $B_\mu(q)$ under projections in Euclidean space for $q>1$. We show
that $B_\mu(q)$ is preserved under almost every orthogonal projection. As an
application, we study the multifractal analysis of the projections of a
measure. In particular, we obtain general results for the multifractal analysis
of the orthogonal projections on $m$-dimensional linear subspaces of a measure
$\mu$ satisfying the multifractal formalism.
