Polymers are generally spatially heterogeneous, either in terms of mor
phology or as blends of various components. Solid state NMR imaging pr
ovides a means of characterizing both the chemical/morphological compo
sition and its spatial variation. Here we discuss multiple-pulse line-
narrowing approaches to acquiring high resolution NMR images and how t
hese sequences can be modified so as to be sensitive to the chemical c
omposition of a sample.