Preferred Vector Image format for use in WPF?

As per the title, what's the preferred image format (or formats) for use in WPF?

My company will hire a designer to design some logos, images, toolbar icons, etc. for use in a WPF application. I was going to ask for Vector Graphics as they are supposed to stretch, shrink, etc without loosing clarity;

However, reading this post Does WPF support reading/writing WMF/EMF files natively? and others has got me worried; IT DOES NOT SEEM LIKE A SIMPLE TASK?! isn't this 开发者_如何学运维what WPF is supposed to handle natively in its sleep ?! stretch, rotate, throw flames, make toast, etc...

The preferred vector image format is XAML. There are a lot of ways for a designer to generate those graphics. Adoble Illustrator for example can use the XAML exporter. The open source tool Inkscape can export to XAML directly, a designer can also draw XAML using Microsoft Expression Design and Microsoft Expression Blend. Literally all vector graphics tool support SVG and there are a lot of ways to convert SVG to XAML.

Don't bother with WMF/EMF it will just look ugly since windows can not render them antialiased.