Where to buy flat graphite stock?

[Thirdgen89GTA]

Need to make a custom sheet for my ESC/Rcv. mounting tray. I rigged up a temporary solution but its not very strong so it was more of a "yeah it'll fit that way" thing.

I tried some searches but ended up with tons of links to graphite powder instead of sheets.

Edit: don't know why I forgot to check McMasterCarr, they have everything.
Still good to hear of alternatives though. Thinking 2mm sheet, thats how thick the stock CF/Graphite parts are.