MNML is on Amazon. It wasn't available when I made my purchase, but this one is similar too... I'm having issues pasting links, so search for memumi note 9 on Amazon. It's a nice matte .3mm case for about $11.
Got this one and its perfect. I had the Spigen Airskin for my Note 8 and this case is exactly the same but different brand. Love the way the fingerprint sensor cut out is not raised but camera is. Helps with false touches. Blue matches my blue perfectly. I have always used these type cases over skins. Basically the same as a skin with a bit more drop protection for scratches only.