A column is also known as a layer. There are several types of layers that you can add in the Xsheet
The most common layer type is the drawing layer. Any time you need to create a vector drawing or import a symbol or image, you can use a drawing layer. You can also create bitmap artwork on a drawing layer.
If you import a picture or bitmap images in your project, they are inserted in a Bitmap layer. If you choose to vectorize your image when you import, the bitmap object will be placed on a Drawing layer. This way, you can have bitmap images mixed with vector drawings on a Drawing layer.
When importing a bitmap image, you have the option of encapsulating the image in a symbol. If you place a non-vectorized bitmap into a symbol, you will still not be able to mix vector drawings with it on the same layer. If you place a vectorized bitmap in a symbol, you must enter the symbol to be able to mix it with vector artwork.
The Colour-Card layer is used to add a plain colour background to a scene. By default, your scene has no background colour and if you render it as a QuickTime movie or image sequence, it will have a black background.
This layer is not visible in the Xsheet view.
You can import sound files to add dialog and sound effects to your project. The sound layer will be added to your Timeline and Xsheet view when you import a sound file in your scene.
In the Xsheet view, the Sound layer is a dark grey colour.