We report X-ray phase-contrast images of voids and glass fibres in a p
olymer matrix. The phase-contrast images are obtained using both a mon
olithic 3-reflection asymmetric channel-cut monochromator and analyser
with 1.54 Angstrom X-rays. The mechanisms of contrast formation in th
e images of voids and glass fibres are discussed in detail and numeric
al simulations of the images are found to agree with the experiments.