Not all vector formats are created equal. While page-layout programs may allow you to import them, some vector file formats do not print satisfactorily.
WMF is intended for placement in applications such as Microsoft Word or PowerPoint. While WMF can contain both vector and raster content, it offers no support for CMYK content. Curved shapes are rendered as choppy, chiseled sections (Figure 5.2). WMF is a very limited format and simply isn’t appropriate for print.