What must a 5e spell-scroll look like?

As a DM i would like to put spell scrolls (magical or otherwise) on exotic surfaces &/or locations. Are there any hard / R.A.W. limits on this? Both scribing & enchantment are expensive in cost and time – obviously complex – yet with minimal description of how this all looks in the end.

Somewhere in the rules (cannot find it now) it was suggested that non-magical / written spells could in or on many places – is this also the case with magical spell scrolls?

Notes: Brief research on paper suggests pressed-wood, skin-leather, cloth-cottons, hemp-grasses &/or papyrus-reeds and more – even inside glass. One assumes fairies or giants write stuff as well. Possibilities abound and seem endless.