The PixelSize property is an obsolete property which was commonly used prior to summer 2013. The TextureScale property has replaced the PixelSize property. The PixelSize property is equivalent to TexutureScale/2. The PixelSize property was originally created to work well with ScaleX and ScaleY values, but since then FlatRedBall.Sprite.TextureScale, Width, and Height have replaced PixelSize, ScaleX, and ScaleY as the most common ways to interact with a Sprite.