The symbols found in Gravity Falls: Journal 3, created by Bill Cipher.
Gravity Falls and everything to do with it are the property of Disney.
-- Spoilers --
Bill drew this language in secret messages throughout the Journal, as well as a wheel which can be used for decoding.
Font from Betrayal At Krondor, (C) 1993 Dynamix / Sierra On-Line. Bitmap typeface that starts and ends most chapters in the greatest computer RPG of all time, "Betrayal At Krondor". Now 100% accurate, thanks to Flowswitch at the xBAK forum. Based on "Venice" by Bill Atkinson (one of the the original Macintosh system fonts) and "Naples" from EA's 'Deluxe Paint II Enhanced'.
A serif version of NCD Receipt. Enjoy. :-)
This is a clone of NCD Receipt