Realistically, you would just sign "PAPER" to mean stationery.
Or "FANCY PAPER"
You could sign, "I need buy fancy paper for writing letters."
STATIONERY (LETTER PAPER)
NOTE: When you do a compound sign, the movement of the signs become simplified. Thus "paper" which normally has two movements, is done with only one movement when you use it as part of a compound sign.
NOTE: If you are looking for the sign that means "stationary" as in "not moving" I recommend you use the STAY sign. See: STAY
Notes: