Get the material which an item text is written on.
materialName = ItemTextGetMaterial()
- String - The name of the material touse for displaying the item text. If nil then the material is "Parchment".
- This is used one the ITEM_TEXT_READY event has been received for a page.
- See FrameXML/ItemTextFrame.lua for examples of how the material is used to select a set of textures.