Microsoft applications use the Metafile vector formats for shapes, icons, clip-art, charts. Also known as WMF and EMF, these graphics offer great flexibility in changing size and attributes like color, line weight and orientation without degrading. Inserted pictures like screen snips and photos are bitmap graphics. Any of pdf2picture's image output formats are welcome in Microsoft Word. When weighing whether to use image or vector format, consider whether you need to edit it later on. If so, choose WMF or EMF in pdf2picture. If it's a screen-snip, you have no choice - it's a bitmap and that won't change. Vector formats allow you more freedom in resizing graphics without loss of quality (resolution). Sometimes, however, only a bitmap will do when working with photos and other true-color images.