A stationery store means lots of materials for other office supplies. Stationery includes materials to be written on by hand or by equipment such as computer printers.

The stationery store will offer many offices and basic stationery; Stationery is a mass noun referring to commercially manufactured writing materials, including cut paper, envelopes, writing implements, continuous form paper, and refers to “a person who sells the materials used in writing, such as paper, pens, pencils, books, copies, markers, colors, ink.”