Wall trims, caves and archaeology 

Designs like ones you'd see on the new pots and things like that, except in the form of a vine-like block. Like how you can place sculk, vines, lichen, on any block surface. That, but with custom and unique designs. To add to that, add some of these designs to naturally generate on some block surfaces in archeological digsites (trail ruins), and very rarely on blocks in caves. Mining it would break it, mining with silk touch would give you the design. Unsure about crafting. 1.20 is about storytelling after all. Also, possibly replace pottery shards with this? for universal use.