I had a (little) hard time finding the word 宣材{せんざい}. It was neither in the Midori dictionary nor Chrome's rikaikun extension. I had to google it.
I found an explanation here on kotobank but not much more. My question is, is it a relatively new word? Or simply it is not considered a "real word" but just a shortened form of 宣伝材料? Although in the second case I would still expect it to pop up in a dictionary such as Midori (maybe with a reference to 宣伝材料).