Stationery

See Dictionary below (not to be mistaken with Stationary, which means staying in one place, not moving).

EX: In our office, paper, pencils and other office materials are kept in the stationery room.

Merriam-Webster Online Dictionary
stationery (noun)
1.
materials (as paper, pens, and ink) for writing or typing
2.
letter paper usually accompanied with matching envelopes