Hypernym for anything you would write on?
Solution 1:
All of the items you describe are writing materials. The Oxford English Dictionary includes a collocation for this under "writing, n.":
d. In sense ‘used or designed for writing upon’, as writing cloth, writing material, writing slate, writing surface. Also writing-book n., writing-paper n. ...
1875 E. H. Knight Pract. Dict. Mech. 2477/2 Table, a tablet..[or] writing-surface.
1888 J. W. Burgon Lives Twelve Good Men II. v. 36 To get out his writing materials, and to scribble.
The hypernym can refer to either surfaces or utensils, depending on context. The OED examples are all from the 19th century, so I looked for a few more recent examples.
Ancient Writing Materials, a University of Michigan website that documents materials used by ancient people for writing: "Ancient writers wrote on a variety of other materials besides papyrus, including pottery, animal hides, wood, and even ancient paper."
A Materials Research Society lesson, "Module 10 Writing Materials," includes this list of examples: "We will identify the properties of different writing materials, including stone, papyrus, parchment, and paper, and discusses the implications of the transition from manual to mechanical and digital printing. "
A National Association for the Education of Young Children guide, "Promoting Preschoolers’ Emergent Writing," gives this advice: "Strategically place writing materials, such as sticky notes, small chalkboards, whiteboards, envelopes, clipboards, journals, stencils, golf pencils, markers, and various types, sizes, and colors of paper throughout the classroom."